English Modal Verbs

A complete set of vocabulary flashcards covering the usage, forms, negative structures, and distinctions of English modal verbs based on the lecture notes.

CAN

A modal verb used to express ability ('I can swim'), possibility ('It can rain today'), informal permission ('Can I go to the bathroom?'), and requests ('Can you help me?'). Its negative form is cannot or can't.

COULD

The past tense of the modal verb 'can' (e.g., 'I could swim when I was a child').

MAY

A modal verb used for possibility that is fairly likely ('It may rain today') and for formal permission ('May I go to the bathroom?'). Its negative form is 'may not' and has no contracted form.

MIGHT

A modal verb used to express possibility that is less certain or less likely than 'may' ('It might rain today'). Its negative form is 'might not' and has no contracted form.

MAY vs. MIGHT

Both express possibility, but 'MAY' indicates something that is more possible/likely, whereas 'MIGHT' indicates something that is less possible/likely.

MUST

A modal verb used for personal obligation coming from the speaker ('I must study') and for rules or instructions ('You must arrive on time'). It is mainly used in the present tense.

MUSTN'T / MUST NOT

The negative form of 'must', used to indicate prohibition (divieto), as in 'You mustn't smoke here'.

HAVE TO

A modal structure conjugated as 'have to' (I/you/we/they) or 'has to' (he/she/it), used for external obligation imposed by laws or outside rules ('I have to work tomorrow'). It can be used with all tenses.

DON'T / DOESN'T HAVE TO

The negative form of 'have to', used to indicate that something is not necessary (lack of obligation), as in 'You don't have to smoke here'.

MUSTN'T vs. DON'T HAVE TO

'Mustn't' indicates prohibition (it is forbidden), while 'don't have to' indicates a lack of necessity (you are not obliged to do it).

SHOULD

A modal verb used for advice and recommendations ('You should study more'), opinions on what is right ('People should respect others'), and expectations of what will probably happen ('The train should arrive at 6'). Negative: 'should not' or 'shouldn't'.

OUGHT TO

A modal verb requiring 'TO' that is used to give advice ('You ought to study more'). Negative form is 'ought not to' (or rarely 'oughtn't').

SHOULD vs. OUGHT TO

Both are used to give advice and share similar meanings, but 'SHOULD' is used frequently, whereas 'OUGHT TO' is used much less often.