- LPU MCA Semester 1
- PEL546
- Unit 3
PEL546 · Unit 3: Modals review
Modal verbs of possibility and necessity
9 practice questions · in the MTE and ETE syllabus
Key points
- Might is weak possibility, can't is impossibility
- Must can mean strong obligation or deduction
- Mustn't forbids, needn't makes optional
- Must have plus a participle deduces about the past
Possibility: may and might (weak: It might snow tonight), could, and can't for impossibility or a strong belief that something is not true (She can't be the manager; she lacks experience).
Deduction: must expresses a strong conclusion from evidence (His car is outside, so he must be at home) and must have + past participle a conclusion about the past (She must have forgotten).
Obligation and advice: must is a strong obligation (You must wear a seat belt), should and ought to give advice (You should see a doctor).
No necessity versus prohibition: needn't or don't have to means not necessary, whereas mustn't means forbidden.
| Modal | Meaning |
|---|---|
| must | strong obligation or deduction |
| mustn't | prohibition |
| needn't, don't have to | not necessary |
| should | advice |
| might | weak possibility |
| can't | impossible |
Exam trap: mustn't and don't have to are not interchangeable.
Try two questions
Choose the correct word: You ___ bring your ID card, but it would help.
- mustn't
- can't
- shouldn't
- needn't
Show the answer
D. Needn't means it is not necessary.
Why not A: Mustn't expresses prohibition.
Why not B: Can't expresses impossibility or prohibition.
Why not C: Shouldn't would advise against bringing it, which contradicts but it would help.
Which sentence expresses weak possibility?
- It can't snow tonight.
- It might snow tonight.
- It will definitely snow tonight.
- It mustn't snow tonight.
Show the answer
B. Might expresses a slight possibility.
Why not A: Can't expresses impossibility.
Why not C: Will definitely expresses certainty.
Why not D: Mustn't expresses prohibition and is not a possibility.