Must have V3 vs. Should have V3 (Perfect Modals) – English Grammar Exercises for B2
Post-concert FOMO (Fear Of Missing Out). You scroll through Instagram and see your close friends’ stories of an absolutely spectacular idol concert, while you chose to stay home and sleep. You are deeply regretting your decision and speculating about what happened based on their posts.
Choose the best answer (A, B, C, or D) to complete each sentence.
1 I watched my friends’ Instagram stories this morning. The concert ______ amazing!
(a) must had been
(b) must be
(c) should have been
(d) must have been
2 I ______ a ticket when they were on sale last month. Now I deeply regret it.
(a) should have bought
(b) must have bought
(c) should buy
(d) should bought
3 Look at those incredible fireworks on their stories! The finale ______ breathtaking.
(a) must of been
(b) must have been
(c) had to be
(d) could be
4 You ______ in bed while your favorite band was performing live just a few miles away!
(a) didn’t should stay
(b) mustn’t have stayed
(c) shouldn’t have stayed
(d) shouldn’t have stay
5 My friend Emma knew all the lyrics. She ______ to their album continuously before the event.
(a) should have listened
(b) must have listen
(c) must listened
(d) must have listened
6 I was feeling a bit tired yesterday, but I ______ that stop me from going to the biggest event of the year.
(a) shouldn’t let
(b) shouldn’t have let
(c) couldn’t have let
(d) didn’t have let
7 Judging by the massive crowd in the videos, the organizers ______ all the tickets in just a few minutes.
(a) should have sold out
(b) must sell out
(c) must have sold out
(d) must have sell out
8 It was my own fault. I ______ my alarm to wake up and secure the early-bird tickets.
(a) should have set
(b) should set
(c) must have set
(d) should of set
9 When I saw the notification for the live stream, I knew I ______ my friends at the stadium instead of staying home.
(a) should to have joined
(b) must have joined
(c) should join
(d) should have joined
10 They are all losing their voices today. They ______ really loud during the performance last night.
(a) must have screamed
(b) should have screamed
(c) had to scream
(d) must have scream
11 Honestly, I ______ more attention to the tour dates. I completely missed the announcement.
(a) must have paid
(b) should pay
(c) should have paid
(d) should had paid
12 The lead singer ______ very emotional because he was crying during the final song in the video.
(a) must have felt
(b) should have felt
(c) must felt
(d) must feel
13 I ______ my favorite pajamas instead of a stunning concert outfit. What a terrible choice!
(a) shouldn’t have chose
(b) shouldn’t have chosen
(c) didn’t have to choose
(d) mustn’t have chosen
14 My friends posted over 50 stories each. They ______ the time of their lives!
(a) should have had
(b) must have had
(c) must have
(d) must had
15 I assumed the concert would be boring, but I ______ such a quick judgment without checking the setlist.
(a) shouldn’t have made
(b) needn’t have made
(c) shouldn’t make
(d) shouldn’t have make
16 The traffic was awful last night according to the news. My friends ______ for hours to get to the venue.
(a) should have waited
(b) must have wait
(c) must have waited
(d) had to wait
17 I decided to save money, but the ticket was only $50! I ______ so cheap about a once-in-a-lifetime experience.
(a) shouldn’t have been
(b) couldn’t have been
(c) shouldn’t be
(d) shouldn’t have be
18 There’s confetti all over my friend’s jacket in the photo. The production team ______ a fortune on special effects.
(a) must of spent
(b) should have spent
(c) must spend
(d) must have spent
19 I skipped the concert because it looked like rain, but the sky was clear all night. I ______ the weather forecast so blindly.
(a) mustn’t have trusted
(b) didn’t need to trust
(c) shouldn’t have trusted
(d) not should have trusted
20 My friends didn’t answer my texts when they got home. They ______ completely exhausted after dancing all night.
(a) must have been
(b) should have been
(c) had to be
(d) must have be
ANSWER KEY & EXPLANATIONS
1 (d)
- Why it is correct: “Must have + V3” (must have been) is used to make a highly logical deduction about a past event based on clear evidence (seeing the Instagram stories).
- Error Analysis:
- (a) Structural Error: Modals must be followed by the base verb “have”, not “had”.
- (b) Common Mistake: Wrong tense. The event happened in the past; “must be” is for present deduction.
- (c) Strong Distractor / Meaning Trap: “Should have been” expresses a missed expectation, which doesn’t fit the context of concluding a fact.
2 (a)
- Why it is correct: “Should have + V3” (should have bought) expresses deep regret about something that was a good idea to do in the past but wasn’t done.
- Error Analysis:
- (b) Strong Distractor: Means “I certainly bought it” (deduction), which contradicts the context of regret.
- (c) Common Mistake: Uses “should + V” (present advice) instead of referring to a past regret.
- (d) Structural Error: Missing the auxiliary verb “have”.
3 (b)
- Why it is correct: “Must have been” expresses a strong, logical assumption about the fireworks display last night.
- Error Analysis:
- (a) Structural Error: “Must of” is a misspelling based on spoken pronunciation; it is grammatically incorrect.
- (c) Common Mistake: “Had to be” implies a past obligation rather than a logical deduction.
- (d) Strong Distractor: “Could be” indicates weak possibility in the present, not a past deduction.
4 (c)
- Why it is correct: “Shouldn’t have + V3” expresses criticism or regret about an action that was done in the past but was a bad idea (staying in bed).
- Error Analysis:
- (a) Structural Error: Incorrect negative formation for modal verbs.
- (b) Strong Distractor: “Mustn’t have V3” is rarely used and does not correctly express regret or self-reproach.
- (d) Structural Error: The verb “stay” is not in the past participle form (stayed).
5 (d)
- Why it is correct: “Must have listened” is a logical deduction: Emma knew all the lyrics, so she definitely listened to the album repeatedly beforehand.
- Error Analysis:
- (a) Strong Distractor: Implies she didn’t listen to it and regrets it, which contradicts the fact that she knew the lyrics perfectly.
- (b) Structural Error: “Listen” is not in the V3 form.
- (c) Structural Error: Missing “have” after the modal verb.
6 (b)
- Why it is correct: Regret over a past action: I should not have allowed fatigue to stop me (but I did).
- Error Analysis:
- (a) Common Mistake: Present tense instead of past.
- (c) Strong Distractor: “Couldn’t have let” means “it was impossible that I let”, which misses the nuance of regret.
- (d) Structural Error: Grammatically incorrect structure.
7 (c)
- Why it is correct: Strong deduction based on evidence (the massive crowd): the tickets were definitely sold out.
- Error Analysis:
- (a) Strong Distractor: Implies they failed to sell out but it would have been a good idea if they did. This contradicts the evidence.
- (b) Common Mistake: Refers to the present/future instead of the past event.
- (d) Structural Error: “Sell” must be in the past participle form (sold).
8 (a)
- Why it is correct: Expressing self-blame: I made a mistake by not setting my alarm.
- Error Analysis:
- (b) Common Mistake: Present tense advice instead of past regret.
- (c) Strong Distractor: “Must have set” means “I definitely set it”, which is factually false in this context.
- (d) Structural Error: Spelling error (“of” instead of “have”).
9 (d)
- Why it is correct: Acknowledging a past mistake: it would have been the right decision to join my friends.
- Error Analysis:
- (a) Structural Error: You cannot put “to” after “should”.
- (b) Strong Distractor: Implies you actually joined them, which is false.
- (c) Common Mistake: Present tense advice.
10 (a)
- Why it is correct: Logical deduction: They lost their voices today, which means they definitely screamed loudly last night.
- Error Analysis:
- (b) Strong Distractor: Implies they didn’t scream but it would have been good if they did. This doesn’t make logical sense here.
- (c) Common Mistake: Expresses past obligation (“were forced to scream”).
- (d) Structural Error: “Scream” is not in the V3 form.
11 (c)
- Why it is correct: Self-reproach: I failed to pay attention to the dates, and I regret it now.
- Error Analysis:
- (a) Strong Distractor: Means “I definitely paid attention”, which contradicts the fact that the announcement was missed.
- (b) Common Mistake: Giving advice for the present/future.
- (d) Structural Error: Must use the base form “have”, not “had”.
12 (a)
- Why it is correct: Concluding a past state based on evidence (crying): he was certainly feeling very emotional.
- Error Analysis:
- (b) Strong Distractor: Implies he wasn’t emotional but he ought to have been. This contradicts the crying evidence.
- (c) Structural Error: Missing the auxiliary verb “have”.
- (d) Common Mistake: Present tense deduction for a past event.
13 (b)
- Why it is correct: Strong regret about a poor choice made in the past (choosing pajamas).
- Error Analysis:
- (a) Structural Error: “Chose” is the V2 form; it must be the V3 form (chosen).
- (c) Common Mistake: “Didn’t have to” means it wasn’t necessary (but you still could). It lacks the strong self-reproach required here.
- (d) Strong Distractor: “Mustn’t have” is structurally awkward and not used to express personal regret.
14 (b)
- Why it is correct: Deducing from the 50+ stories: they definitely experienced a wonderful time.
- Error Analysis:
- (a) Strong Distractor: Implies they didn’t have a good time, which contradicts the evidence.
- (c) Common Mistake: Present tense deduction.
- (d) Structural Error: “Must had” is grammatically incorrect.
15 (a)
- Why it is correct: Regretting a past assumption: I made a quick judgment, and that was a bad idea.
- Error Analysis:
- (b) Strong Distractor / Meaning Trap: “Needn’t have made” means “I did it, but it was unnecessary/a waste of time.” While close, “shouldn’t have” is much better suited to express the deep regret of FOMO.
- (c) Common Mistake: Present tense advice.
- (d) Structural Error: “Make” is not in the V3 form.
16 (c)
- Why it is correct: Guessing what happened based on the news (awful traffic): they certainly waited for hours.
- Error Analysis:
- (a) Strong Distractor: Implies they should have waited (but didn’t). Nonsensical in this context.
- (b) Structural Error: Missing the V3 form (waited).
- (d) Common Mistake: “Had to wait” states a past fact without the nuance of making a deduction from a clue (the news).
17 (a)
- Why it is correct: Regretting being stingy: It was a mistake to be so cheap over $50
- Error Analysis:
- (b) Strong Distractor: “Couldn’t have been” means “it was impossible that I was cheap”, which is factually false since you were cheap.
- (c) Common Mistake: Refers to the present.
- (d) Structural Error: The verb “be” must be in the past participle form (been).
18 (d)
- Why it is correct: Deduction based on physical evidence (confetti): the team definitely spent a lot of money.
- Error Analysis:
- (a) Structural Error: “Must of” is incorrect grammar.
- (b) Strong Distractor: Implies they didn’t spend money but should have. This contradicts the evidence of confetti everywhere.
- (c) Common Mistake: Present tense deduction.
19 (c)
- Why it is correct: Acknowledging a past mistake: trusting the weather forecast was a bad idea.
- Error Analysis:
- (a) Strong Distractor: “Mustn’t have trusted” does not carry the meaning of “it was a bad idea to trust.”
- (b) Common Mistake: “Didn’t need to trust” loses the strong tone of regret.
- (d) Structural Error: Incorrect placement of “not”.
20 (a)
- Why it is correct: Logical assumption: they aren’t answering texts because they are certainly exhausted from last night.
- Error Analysis:
- (b) Strong Distractor: Implies they should be exhausted but aren’t.
- (c) Common Mistake: Implies past obligation (they were forced to be exhausted).
- (d) Structural Error: “Be” must be in the V3 form (been).
GRAMMAR POINTS TO REMEMBER
- Must have + V3: Used to express a highly logical and certain deduction about a PAST event based on clear signs or evidence (e.g., Seeing confetti on a jacket -> deducting that they must have spent a fortune on effects).
- Should have + V3 / Shouldn’t have + V3: Used to express regret, self-reproach, or criticism about something that ought to / ought not to have been done in the past, but the opposite actually happened.
- Common Mistakes:
- Using “Should + V” or “Must + V” when the context refers to a regret or deduction about a past event (yesterday, last night).
- Confusing “Must of V3” or “Should of V3” (which are spoken/pronunciation errors) with the standard written form, which strictly requires “have”.
- Meaning Traps: Always clarify the speaker’s intention. Is the speaker Deducing a past event (Must have V3) or Regretting a past event (Should have V3)? The same grammatically correct structure can appear in the options, but the context (regret vs. affirming a truth) ultimately determines the correct answer.