Past Modals: should have, must have, might have
Past modals talk about the past with an opinion or guess. At B1 the key ones are should have (criticism/regret), shouldn't have (a past mistake), and might have / could…
Past modals talk about the past with an opinion or guess. At B1 the key ones are should have (criticism/regret), shouldn’t have (a past mistake), and might have / could have / must have / can’t have (past deduction).
The forms and meanings
| Modal | Meaning | Example |
|---|---|---|
| should have + pp | the right thing to do, but didn’t | You should have called. |
| shouldn’t have + pp | a past mistake | I shouldn’t have eaten that. |
| must have + pp | sure it happened | She must have left early. |
| might/could have + pp | maybe it happened | He might have forgotten. |
| can’t have + pp | sure it didn’t happen | They can’t have finished already. |
The pattern is fixedAlways: modal + have + past participle. The modal never changes, and “have” stays as “have”: “She should have gone,” not “She should has gone.”
Examples from EduCareer
- You should have joined the live class — it was great.
- Aisha must have studied a lot; her score was perfect.
- Omar might have missed the email about the schedule.
Tutor tip for Arabic speakersIn speech, “have” sounds like “of” (“should’ve”). Never write “should of” — it’s always should have. Keep the three parts together: should have done, must have gone, might have seen.
Common mistakes
- You should of called. → You should have called.
- She must have went. → She must have gone.
- He should have studies more. → He should have studied more.
Practise with the 20 questions below.
Check your understanding
Answer the questions below. You will see instantly if you are right.
1."You ___ called me — I was worried."
should have + pp.
2."I ___ eaten so much; now I feel sick."
past mistake.
3."Her score was perfect. She ___ studied hard."
sure it happened → must have.
4."He didn't reply. He ___ missed the email."
possible → might have.
5."They started 5 minutes ago. They ___ finished yet."
sure not → can't have.
6.The fixed pattern is:
modal + have + past participle.
7.Which is correct?
have, never 'of'.
8.Which is correct?
past participle 'gone'.
9."I'm tired. I ___ stayed up so late."
regret a mistake.
10."The ground is wet. It ___ rained."
evidence → must have.
11."He's not here yet. He ___ got lost."
possible → might have.
12."You ___ told her! Now everyone knows."
criticism of a mistake.
13.'should've' is short for:
should have.
14."They ___ left — their car is gone."
sure → must have.
15."She ___ seen the message; she never read it."
sure not → can't have.
16."We ___ booked earlier; now it's full."
regret → should have.
17."He ___ forgotten — or maybe he's just late."
possibility → could have.
18.Past participle of 'do':
do – did – done.
19."You ___ worried — everything was fine."
the worry was unnecessary.
20."The exam was easy. It ___ been hard for her."
sure not → can't have.
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