In the

    United States Court of Appeals
                 For the Seventh Circuit
                     ____________________
No. 18-3000
ROMUALD TYBURSKI,
                                                  Plaintiff-Appellant,
                                 v.

CITY OF CHICAGO,
                                                 Defendant-Appellee.
                     ____________________

         Appeal from the United States District Court for the
           Northern District of Illinois, Eastern Division.
              No. 16-cv-09228 — John Z. Lee, Judge.
                     ____________________

       ARGUED APRIL 20, 2020 — DECIDED JULY 1, 2020
                ____________________

   Before WOOD, Chief Judge, and SYKES and ST. EVE, Circuit
Judges.
    ST. EVE, Circuit Judge. In 2014, Romuald (“Roman”) Tybur-
ski, then age seventy-four, applied for a promotion with his
employer, the City of Chicago’s Department of Water Man-
agement, but the City rejected his application. Tyburski sued,
claiming that the City denied him the promotion because of
his age in violation of the Age Discrimination in Employment
Act (“ADEA”), 29 U.S.C. §§ 621–634. He also brought a hostile
2                                                 No. 18-3000

work environment claim under the ADEA regarding harass-
ment he allegedly experienced at two Department of Water
Management facilities: Central Park Pumping Station (“Cen-
tral Park”) and Jardine Water Purification Plant (“Jardine”).
The district court ultimately granted summary judgment in
favor of the City.
    Tyburski has not supplied evidence showing that his age,
rather than his failing score on the requisite verbal exam, was
the reason he missed out on the desired promotion. Further-
more, assuming a hostile work environment claim is cogniza-
ble under the ADEA, Tyburski failed to present sufficient ev-
idence for a factfinder to conclude that the purported harass-
ment he experienced was severe or pervasive. And Tyburski
failed to exhaust this claim regarding conduct that allegedly
occurred at Jardine, as he did not file a charge with the Equal
Employment Opportunity Commission (“EEOC”) reporting
that conduct. Summary judgment was therefore appropriate,
and we affirm.
                       I. Background
    Roman Tyburski currently works for the City of Chicago
as an engineer with the Department of Water Management.
The City hired Tyburski as an Operating Engineer – Group C
(“OEC”) in 1993, when Tyburski was fifty-three years old. In
2013, Tyburski received a promotion to his current position,
Operating Engineer – Group A (“OEA”). Applicants seeking
to become OEAs must successfully pass a written and verbal
exam. At the time of his promotion to OEA, Tyburski was sev-
enty-three years old. In September 2013, after Tyburski re-
ceived his promotion, the City assigned him to Central Park.
No. 18-3000                                                     3

A. Application for Assistant Chief Promotion
    In 2014, one year after his OEA promotion, Tyburski ap-
plied for another—this time, to the position of Assistant Chief
Operating Engineer (“ACOE”). Successful candidates must
pass a three-part examination: two parts written and one part
verbal. To pass each of the written exams, applicants must
score at least seventy percent; to pass the verbal, sixty percent.
On the verbal exam, each of the five questions could receive a
possible score of five points. Raters multiplied these scores by
four to obtain a total score out of one hundred points.
   Two Chief Operating Engineers—James McCarthy (then
age sixty-two), who had previously interviewed Tyburski in
the course of his successful application to become an OEA,
and Maurice Walsh (then age fifty-three)—conducted the ver-
bal ACOE exams. McCarthy and Walsh used the City’s Hu-
man Resources standard exam questions, answers, and scor-
ing rubric.
    Twenty-nine of the thirty-two candidates who completed
the written exam passed, including Tyburski. Thirteen of
these twenty-nine candidates passed the verbal exam and re-
ceived a promotion to ACOE. The passing candidates ranged
in age from twenty-eight to fifty-six, and seven of them were
over age forty.
    Walsh gave Tyburski a rating of three for the first of the
five questions and a rating of two for the other four questions.
When multiplied, this resulted in a total score of forty-four.
McCarthy gave Tyburski a rating of two for all five questions,
for a total score—once multiplied—of forty. Averaging these
scores together, Tyburski received a forty-two percent on the
4                                                No. 18-3000

verbal exam, below the passing threshold of sixty. The City
did not promote him.
   During the verbal exam, one question asked applicants to
describe the steps necessary to put a centrifugal pump into
service. Tyburski asked McCarthy and Walsh if he could an-
swer the question by explaining the process of putting a tur-
bine powered centrifugal pump into service. McCarthy and
Walsh gave him permission to do so. Tyburski proceeded to
answer the question in that manner. The completed rubrics
evaluating Tyburski’s interview demonstrate that Tyburski
did not receive full credit because his answer was limited to
discussing the turbine powered centrifugal pump.
   In October 2014, Tyburski filed an internal grievance com-
plaining about his failure to receive the promotion to ACOE.
The grievance alleged that his department “promoted an En-
gineer of lesser rank (OEC) and lesser seniority with no su-
pervisory experience as required ….”
B. Alleged Harassment and Retaliation at Central Park
    Tyburski contends his coworkers at Central Park de-
meaned and harassed him because of his age. Brian Sumner,
an OEA who would sometimes take on the role of ACOE
when the usual ACOE had the day off, would tell Tyburski he
was too old and that people of Tyburski’s age should not hold
the OEA position. Tyburski claims that Sumner would make
such comments at “every opportunity.” Whenever Tyburski
complained about Sumner’s comments, Sumner would re-
frain for “a week or two weeks” before resuming again. In re-
sponse to Tyburski’s complaints, the City had Sumner take
the subordinate role of OEC and report to Tyburski on the
No. 18-3000                                                   5

days that Tyburski was working, so Tyburski would not have
to take orders from him.
    Another colleague, OEC Jeff Worden, mentioned Tybur-
ski’s age “about three or four times” during their shifts to-
gether. In one incident in 2012, before they both received a
transfer to Central Park, Tyburski asked Worden if he could
join him for laps during lunch, but Worden responded, “Ro-
man, you [sic] too old. You cannot keep up with me.” In an-
other incident in 2015, when Tyburski criticized Worden’s
performance, Worden responded that Tyburski was “f**king
old” and did not know what he was doing.
    Tyburski also cites harassment from Carl Sanderson, an-
other OEC. Although most of the time Tyburski and Sander-
son had no conflicts and a good working relationship, Tybur-
ski claims Sanderson harassed him in—at most—five separate
incidents. Tyburski testified that on two occasions, around
late 2014 or early 2015, Sanderson told him, “Roman, you are
old and you [sic] piece of shit.”
    Tyburski also complains about conduct from Brandon
Mecher, an ACOE and his superior. Tyburski alleges that
Mecher implied he was too old for his job and assigned him
tasks beneath his position, such as boiler water tests. Tyburski
claims that he has never seen another OEA perform these
tasks. Tyburski also testified that when he complained about
his assignment to these tasks, Chief Operating Engineer An-
dre Holland told him to “just do it.”
   On April 21, 2015, Tyburski filed his first of three charges
with the EEOC. In that charge, Tyburski complained that the
City denied him a promotion due to his age, that Sumner had
subjected him to discriminatory age-related comments, and
6                                                 No. 18-3000

that his coworkers demeaned, ridiculed, and harassed him
because of his age and because he filed a complaint. Tyburski
did not discuss his EEOC charge with his coworkers.
    On June 1, 2015, while Tyburski was closing a boiler room
valve, Sumner told him, “Roman, you don’t know what the
f**k you doing.” Sumner then grabbed him and yanked him
away from the valve. Tyburski does not claim that Sumner
said anything about his age during this interaction.
    On July 2, 2015, Tyburski filed a second charge with the
EEOC alleging age discrimination and retaliation for his first
EEOC charge. Specifically, Tyburski alleged Sumner “har-
assed and physically intimidated” him by “shoving [him] into
a steel object causing injury.” He also alleged that Pumping
Engineer Mark O’Malley encouraged Sumner to harass and
intimidate him to force him to quit. He also reported receiving
a memo temporarily reassigning him in retaliation for his
original EEOC charge (a threat that never came to fruition),
and that “[o]ther employees who did not file an EEOC dis-
crimination complaint have not been harassed, physically in-
timidated, and threatened with an undesirable job transfer.”
Like his first EEOC charge, Tyburski did not discuss this
EEOC charge with his coworkers.
    On August 11, 2015, Mecher assigned Tyburski to mop
and scrub the garage floor at Central Park, which Tyburski
believed was improper because he did not park his car in the
garage and OEAs typically do not mop or scrub floors. Tybur-
ski then received a “counseling note” explaining that if he did
not scrub or mop the floor, Chicago police would escort him
out of the facility. Tyburski complained internally about his
assignment to these tasks.
No. 18-3000                                                   7

    On August 19, 2015, Tyburski filed his third EEOC charge,
this time alleging that Mecher retaliated against him for filing
prior charges by harassing him and requiring him to sweep
and mop a garage floor, despite the absence of these tasks
from the duties listed in his job description. He further ex-
plained, “Mr. Mecher told me, at the time he was hired to
work at the Central Park location, where I work, that ‘Group
A Engineers are not to do any cleaning.’ Therefore, his actions
against me were clearly meant to demean, harass, or force me
to quit my job.” As with his first two EEOC charges, Tyburski
did not discuss this EEOC charge with his coworkers.
    On September 8, 2015, Mecher told Tyburski he was “re-
ally stupid” and “did not know what he was doing.” In re-
sponse, Tyburski swung a foot-long wrench he was carrying,
hitting a steel bench in front of him, and told Mecher to stop
harassing him. As a consequence of his behavior, Tyburski
was asked to leave the station. The City Department of Hu-
man Resources investigated the incident, resulting in Tybur-
ski receiving a one-day suspension.
C. Transfer to Jardine
    After the altercation with Mecher, Deputy Commissioner
Alan Stark reassigned Tyburski from Central Park to Jardine,
consistent with department practice after a violent incident.
Tyburski has several complaints about his time at Jardine.
First, Tyburski contends he was transferred to Jardine be-
cause of his age. Second, Tyburski alleges that several of his
Jardine coworkers made comments to him about retirement,
although he only specifically identifies Mark O’Malley as a
culprit. Third, Tyburski claims he did not receive any training
at Jardine despite new job duties there, which deprived him
an opportunity to receive an ACOE promotion. Fourth,
8                                                     No. 18-3000

Tyburski states he was not given a chair for months, and
when he did receive a chair, it was heavy and he had to lug it
a quarter mile to his work station. Fifth, Tyburski complains
about his assignment to menial duties, such as cleaning filter
tables in a cold and polluted room. And, finally, Tyburski pro-
tests that he received temporary time sheets without his name
pre-printed and that his engineering license hung on a lower
tier of a wall than his seniority deserved. When Tyburski com-
plained about his license placement to Paul Gutierrez, ACOE
at Jardine, Gutierrez responded “you shouldn’t be here,” and
“[w]herever you go you cause trouble.”
D. Procedural History
    Tyburski filed this action against the City bringing non-
promotion and hostile work environment claims under the
ADEA. The City moved for summary judgment, and the dis-
trict court granted the City’s motion. In doing so, the court
first determined that Tyburski failed to establish a prima facie
case under the traditional burden-shifting framework de-
scribed in McDonnell Douglas Corp. v. Green, 

(1973), because he failed to point to at least one similarly situ-
ated younger comparator—here, someone who also scored
below the sixty-percent minimum on the verbal exam and
was nevertheless promoted. The court further concluded that,
even if Tyburski had established a prima facie case, he failed
to present any evidence that the forty-two percent he received
on his verbal exam was pretext for age discrimination. In ad-
dition, the court analyzed the evidence as a whole, pursuant
to our decision in Ortiz v. Werner Enters., Inc., 

(7th
Cir. 2016), and determined that the evidence indicated that
Tyburski’s failing verbal exam score, not age discrimination,
disqualified him from the promotion. The district court also
No. 18-3000                                                     9

concluded that Tyburski did not present sufficient evidence
allowing a jury to find that he faced a hostile work environ-
ment at Central Park, and that he failed to exhaust his claim
as pertains to conduct that occurred at Jardine.
   Tyburski now appeals.
                         II. Discussion
   We review a district court’s summary judgment ruling de
novo. Hall v. City of Chicago, 

, 950 (7th Cir. 2020).
Summary judgment is appropriate when “there is no genuine
dispute as to any material fact and the movant is entitled to
judgment as a matter of law.” Fed. R. Civ. P. 56(a). Although
we construe “all facts and make all reasonable inferences in
the nonmoving party’s favor, the moving party may succeed
by showing an absence of evidence to support the non-mov-
ing party’s claims.” Parkey v. Sample, 

, 1165 (7th
Cir. 2010) (internal citation omitted).
A. Non-Promotion Claim
   Tyburski argues that the City denied his application for a
promotion to ACOE because of his age. No evidence in the
record supports his claim.
    “The ADEA protects workers 40 years of age and older
from age-based employment discrimination.” Wrolstad v.
Cuna Mut. Ins. Soc’y, 

, 454 (7th Cir. 2018). To re-
cover under a theory of disparate treatment in the ADEA con-
text, “it’s not enough to show that age was a motivating factor.
The plaintiff must prove that, but for his age, the adverse ac-
tion would not have occurred.”

v. MCI
Commc’ns Servs., Inc., 

, 455 (7th Cir. 2009)). A fail-
ure to promote an employee can be an adverse employment
action under the ADEA. See, e.g., Grayson v. City of Chicago, 317
10                                                   No. 18-3000

F.3d 745, 748 (7th Cir. 2003); Baron v. City of Highland Park, 

, 338 (7th Cir. 1999).
    “[T]he singular question that matters in a discrimination
case [is]: ‘[W]hether the evidence would permit a reasonable
factfinder to conclude that the plaintiff’s race, ethnicity, sex,
religion, or other proscribed factor caused the discharge or
other adverse employment action.’” Johnson v. Advocate Health
and Hosps. Corp., 

, 894 (7th Cir. 2018) (quoting

). One method a plaintiff may utilize to
present this evidence is the McDonnell Douglas framework.
McDaniel v. Progress Rail Locomotive, Inc., 

, 367–68
(7th Cir. 2019). “Under this approach, the plaintiff must show
evidence that ‘(1) she is a member of a protected class, (2) she
was meeting the defendant’s legitimate expectations, (3) she
suffered an adverse employment action, and (4) similarly sit-
uated employees who were not members of her protected
class were treated more favorably.’” Skiba v. Illinois Cent. R.R.
Co., 

, 719 (7th Cir. 2018) (quoting Carson v. Lake
Cty., Ind., 

, 533 (7th Cir. 2017)). “If the plaintiff
meets each element of her prima facie case, ‘the burden shifts
to the defendant to articulate a legitimate, nondiscriminatory
reason for the adverse employment action, at which point the
burden shifts back to the plaintiff to submit evidence that the
employer’s explanation is pretextual.’”

(quoting

).
   A plaintiff may put forth and a court may analyze evi-
dence using the McDonnell Douglas framework, but neither
must do so. 

. The McDonnell Douglas
framework “is merely one way of culling the relevant evi-
dence needed to demonstrate whether a reasonable factfinder
could conclude that an employer engaged in an adverse
No. 18-3000                                                   11

employment action based on the plaintiff’s” age or another
proscribed factor. 

. “However the
plaintiff chooses to proceed, at the summary judgment stage
the court must consider all admissible evidence to decide
whether a reasonable jury could find that the plaintiff suf-
fered an adverse action because of her age.” 

(quoting 

). Accordingly, as we an-
nounced in Ortiz, courts must assess the evidence “as a whole,
rather than asking whether any particular piece of evidence
proves the case by itself,” regardless of whether the court also
analyzes the evidence pursuant to McDonnell Douglas. 

.
    Tyburski argues that the district court improperly evalu-
ated his non-promotion claim because it applied two different
standards—first, the McDonnell Douglas framework and, sec-
ond, the holistic approach under Ortiz—when Ortiz outlines
the only valid method. Tyburski is correct that there is only
one standard regardless of the approach, but this argument
lacks merit because, here, the district court properly analyzed
the evidence (or lack thereof) supporting Tyburski’s non-pro-
motion claim. The district court concluded that “the evidence
viewed as a whole indicates that Tyburski’s failure on the ver-
bal portion of the Assistant Chief Exam is what disqualified
him from promotion” and “even when viewing this evidence
cumulatively … no reasonable jury could find that Tyburski’s
age was the but-for reason that he was not promoted.” In
other words, the district court did not improperly apply two
tests; it evaluated the evidence holistically, as Ortiz requires.
As long as the court considers the evidence as a whole, it may
12                                                  No. 18-3000

also use the McDonnell Douglas framework as a supplemental
tool.
    Tyburski further argues that the court incorrectly applied
the McDonnell Douglas framework by defining the compara-
tive employee at issue as “a younger employee who was pro-
moted despite scoring less than 60 percent on the oral exam.”
This argument similarly falls short. The district court identi-
fied the appropriate comparator—a younger employee who,
like Tyburski, failed the verbal exam but nevertheless re-
ceived a promotion. Moreover, even if the determination of
the comparator were an error, the district court correctly con-
cluded that, assuming Tyburski could establish a prima facie
case, his claim still failed because he was unable to demon-
strate pretext.
    The heart of Tyburski’s non-promotion claim is that the
City improperly scored his verbal exam and therefore used
his failing grade as pretext to deny him the promotion. The
City is permitted to set the necessary qualifications for an em-
ployment position. See Schaffner v. Glencoe Park Dist., 

, 621 (7th Cir. 2001) (“What the qualifications for a position
are … is a business decision, one courts should not interfere
with. We do not tell employers what the requirements for a
job must be.”). Tyburski did not meet these qualifications: he
scored a forty-two percent, well below the sixty percent nec-
essary to obtain a promotion. As long as there was no sham
scoring, this dooms his claim.
    Naturally, Tyburski attempts to argue that there was, in
fact, sham scoring. He points to his score on the question
about putting a centrifugal pump into service. He complains
that, even though the interviewers permitted him to answer
with regards to a turbine powered centrifugal pump, they did
No. 18-3000                                                   13

not give him full credit for his answer. The score Tyburski re-
ceived, however, does not demonstrate discrimination. First,
receiving permission to answer a question in a certain way
did not guarantee Tyburski full credit if he answered in that
way. The interviewers may have assumed, for example, that
Tyburski’s choice to respond with regards to a turbine pow-
ered centrifugal pump meant he was unable to answer the
question more broadly, or Tyburski may still have faltered on
parts of the answer independent of its turbine-powered focus.
Second, even if we credited Tyburski’s self-assessment of the
adequacy of his answer, receiving full credit on that answer
would not have raised his score to passing—he would have
received a fifty-four percent, still below the sixty percent
threshold. And third, even if it were the case that an adjust-
ment on that answer alone was the difference between a pass-
ing and failing grade, Tyburski has not presented any evi-
dence of pretext to explain the grading. To show pretext, a
plaintiff “must do more than simply allege that an employer’s
stated reasons are inaccurate; he must still have some circum-
stances to support an inference that there was an improper
motivation proscribed by law.” Benuzzi v. Bd. of Educ. of the
City of Chicago, 

, 663 (7th Cir. 2011) (quoting
McGowan v. Deere & Co., 

, 581 (7th Cir. 2009)). Ty-
burski has pointed to no evidence of improper motivation,
other than the interviewers’ knowledge of his age relative to
that of the other candidates. This is not enough.
   On appeal, Tyburski also offers a new argument: that he
should have received a higher score on all of the questions,
not only the one about the centrifugal pump. Tyburski
waived this argument. G & S Holdings LLC v. Cont’l Cas. Co.,

, 538 (7th Cir. 2012) (“[A] party waives an argu-
ment by failing to make it before the district court.”). Tyburski
14                                                  No. 18-3000

should have tested and developed this novel theory of the
facts in the district court; it would have undoubtedly led to
greater discovery about the exam and its scoring as a whole.
To allow Tyburski to present this argument here would deny
the City a sufficient opportunity to respond. See generally Her-
nandez v. Cook Cty. Sheriff’s Office, 

, 913 (7th Cir.
2011).
    Even if Tyburski had not waived this argument, he never-
theless failed to demonstrate improper scoring. The standard
rubric interviewers used to evaluate candidates lists bullet
points with potential components of the answers for each
question. Tyburski argues for the first time on appeal that he
should have received a point for each bullet point the inter-
viewer checked off. To be sure, McCarthy testified that the
number of bullet points the applicant addressed in his answer
was related to the ultimate score the applicant received, but the
evidence does not suggest that the number of points given for
each question corresponds exactly to how many of the bullet
points the applicant mentions. Indeed, four of the five ques-
tions had more than five bullet points, suggesting that the
number of bullet points did not directly equate to the score
received. In addition, Walsh’s explanation of the verbal exam
demonstrates that grading was not nearly as rigid as Tyburski
suggests. Walsh explained that the interviewers received a
rating guide that provides examples illustrating the differ-
ences between answers meriting a score of 1, 3, or 5, but inter-
viewers did not “slavishly” adhere to the examples. He fur-
ther noted that the interviewers are allowed to grant points
for any relevant information the candidate provides in an-
swer to a question, and are thus not strictly limited to award-
ing points for the bullet points on the scoring rubric. Cer-
tainly, the fact that two interviewers assigned scores and then
No. 18-3000                                                     15

averaged them suggests that there is some element of subjec-
tivity in the process.
    Lastly, even if Tyburski could show improper scoring, he
does not put forth any evidence that could prove that his age,
rather than the quality of his answers, motivated the inter-
viewers to fail him. An error in scoring is not enough to prove
discrimination, as long as the employer does not act for “a for-
bidden reason.” 

. Similarly, the use of
subjective criteria alone does not suffice as evidence of pre-
text. Tyburski also must point to some “objective evidence in-
dicating that the subjective evaluation is a mask for discrimi-
nation.” Montgomery v. Am. Airlines, Inc., 

, 396 (7th
Cir. 2010) (quoting Sattar v. Motorola, Inc., 

, 1170
(7th Cir. 1998)). He failed to do so.
B. Hostile Work Environment Claims
   We have “assumed, but never decided, that plaintiffs may
bring hostile environment claims under the ADEA.” Racicot v.
Wal-Mart Stores, Inc., 

, 678 (7th Cir. 2005) (citing
Bennington v. Caterpillar, Inc., 

, 660 (7th Cir. 2001);
Halloway v. Milwaukee Cty., 

, 827 (7th Cir. 1999)).
The determination whether a plaintiff can bring such a claim
can wait for another day, though. Even assuming a hostile
work environment claim is cognizable under the ADEA, Ty-
burski fails to provide evidence to support such a claim.
   1. Jardine
    To bring an ADEA claim in federal court, a plaintiff must
first raise it in a charge before the EEOC. Ajayi v. Aramark Busi-
ness Servs., Inc., 

, 527 (7th Cir. 2003); see 29 U.S.C.
§ 626(d)(1). “The primary purpose of the EEOC charge re-
quirement is twofold: it gives the EEOC and the employer a
16                                                     No. 18-3000

chance to settle the dispute, and it gives the employer notice
of the employee’s grievances.” Huri v. Office of the Chief Judge
of the Circuit Court of Cook Cty., 

, 831 (7th Cir.
2015); see also Ezell v. Potter, 

, 1046 (7th Cir. 2005).
   To determine whether a plaintiff has exhausted his claims,
we look to
     whether the allegations are like or reasonably re-
     lated to those contained in the EEOC complaint. If
     they are, then we ask whether the current claim rea-
     sonably could have developed from the EEOC’s in-
     vestigation of the charges before it. Claims are rea-
     sonably related if there is a factual relationship be-
     tween them. At a minimum, this means that the
     EEOC charge and the complaint must describe the
     same conduct and implicate the same individuals.

(internal citations omitted).
    Tyburski failed to exhaust his claim as it pertains to
Jardine. None of Tyburski’s three EEOC charges allege any
age-related harassment while he worked at Jardine. Indeed,
Tyburski filed all of the charges prior to his transfer to Jardine
in September 2015. Nearly all of the conduct Tyburski com-
plains of that allegedly occurred at Jardine—the denial of a
chair, the refusal to provide him with training, his assignment
to clean filter tables in a cold and polluted room, the absence
of his name from time sheets, and the low wall placement of
his engineering license—does not overlap with the conduct
Tyburski alleged at Central Park. And although his second
EEOC charge references one employee who also worked at
Jardine—O’Malley—the charge claims only that O’Malley
urged Sumner, a Central Park employee, to harass and
No. 18-3000                                                    17

intimidate Tyburski. With only information about Central
Park, a reasonable EEOC investigation into the charges Ty-
burski filed before his transfer would not have led to an in-
vestigation of conduct alleged to have taken place at Jardine.
See Connor v. Illinois Dep’t. of Natural Res., 

, 680
(7th Cir. 2005) (concluding it was impossible for the EEOC to
undertake a preliminary investigation of non-promotion that
occurred a month after the EEOC charge was filed). We there-
fore address only whether Tyburski presented sufficient evi-
dence to demonstrate an issue of fact exists as to whether he
faced a hostile work environment at Central Park.
   2. Central Park
    For a plaintiff to prevail on a hostile work environment
claim, she must show that: “(1) she was subject to unwelcome
harassment; (2) the harassment was based on her [age]; (3) the
harassment was sufficiently severe or pervasive so as to alter
the conditions of her employment and create a hostile or abu-
sive atmosphere; and (4) there is a basis for employer liabil-
ity.” 

(citing Cooper-Schut v. Visteon
Auto. Sys., 

, 426 (7th Cir. 2004)). “A hostile work
environment is one that is both objectively and subjectively
offensive.”

v. City of Boca Raton, 

, 787 (1998)). “In evaluating the objective offensiveness of
a plaintiff’s work environment, we consider all of the circum-
stances, including frequency and severity of the conduct,
whether it is humiliating or physically threatening, and
whether it unreasonably interferes with an employee’s work
performance.”

(citing Luckie v. Ameritech Corp.,

, 714 (7th Cir. 2004)). Even insults specifically ref-
erencing age do not necessarily rise to the level of actionable
harassment. See

(“examples of boorish behavior” are
18                                                   No. 18-3000

not necessarily “actionable age harassment”). Mere “personal
animosity or juvenile behavior” by coworkers is similarly in-
sufficient. Brown v. Advocate South Suburban Hosp., 

, 1105 (7th Cir. 2012) (quoting Shafar v. Kal Kan Foods, Inc.,

, 666 (7th Cir. 2005)).
    As a preliminary matter, Tyburski failed to present evi-
dence establishing employer liability, and his hostile work en-
vironment claim fails on this basis alone. The Supreme Court
has held that an employer “may be vicariously liable for an
employee’s unlawful harassment only when the employer
has empowered that employee to take tangible employment
actions against the victim,” such as “hiring, firing, failing to
promote, reassignment with significantly different responsi-
bilities, or a decision causing a significant change in benefits,”
and when the harassment culminates in such a tangible em-
ployment action. Vance v. Ball State Univ., 

, 431,
424 (2013). In other words, an employer is strictly liable when
a supervisor performs a tangible employment action against
an employee.

Tyburski has not identified any har-
assment at the hands of supervisors, and therefore cannot pre-
vail on that theory. Indeed, the one supervisor he mentions—
ACOE Mecher—only implied comments about his age. And in
any event, ACOEs are not authorized to hire, fire, demote, or
transfer OEAs. Thus, even if Mecher had harassed Tyburski,
the City could not be held strictly liable for his behavior.
    Alternatively, if the harassing employee is a coworker ra-
ther than a supervisor, “the employer is liable only if it was
negligent in controlling working conditions.” Id.; see also

(listing examples where an employer may be negligent
in failing to prevent harassment from taking place). Tyburski
has failed to put forth any evidence of negligence on the part
No. 18-3000                                                     19

of the City. Instead, the evidence shows that, when Tyburski
complained about Sumner, the City took prompt action such
that Sumner would temporarily refrain from making com-
ments. The City also reassigned Sumner to a subordinate po-
sition on days when Tyburski worked so Tyburski would not
have to take orders from him.
      Tyburski’s hostile work environment claim also fails on
the merits. Tyburski contends that Worden and Sanderson,
two of his subordinates, made age-related comments to him,
but he has not demonstrated that an issue of fact exists as to
whether these comments were so threatening or pervasive
that they could rise to the level of an actionable claim. Indeed,
Tyburski testified that he and Sanderson had a good relation-
ship, despite (at most) five age-related comments Sanderson
made. And Tyburski alleges that Worden made only three or
four age-related comments over a period of as many years.
No reasonable jury could determine that harassment was
“pervasive” at this frequency. See, e.g., 

–
78 (plaintiff failed to demonstrate the harassment she experi-
enced was pervasive where she only “described a limited
number of incidents that are more reflective of run of the mill
uncouth behavior than an atmosphere permeated with dis-
criminatory ridicule and insult.”).
    Furthermore, Tyburski has not presented evidence that
the alleged harassment was retaliatory. For a superior to have
retaliated against an employee based on protected activity,
the superior must have had knowledge of that protected ac-
tivity. Stephens v. Erickson, 

, 788 (7th Cir. 2009);
Treadwell v. Office of Ill. Sec’y. of State, 

, 782 (7th
Cir. 2006). Tyburski has failed to produce any evidence that
his coworkers were aware of his EEOC charges; in fact, the
20                                                 No. 18-3000

record shows he did not discuss his charges with his col-
leagues. We need not assume that his coworkers were notified
of these charges without any evidence to support that as-
sumption.
                       III. Conclusion
   Tyburski failed to present any evidence that age-related
discrimination motivated the City’s decision not to promote
him, and he did not present sufficient evidence for a reasona-
ble jury to conclude that he faced harassment so pervasive
and severe that it would rise to the level of a hostile work en-
vironment claim. The district court correctly granted sum-
mary judgment, and we therefore AFFIRM.