Modal Verbs and Their Usage in English Grammar

May - Might: she may have missed the bus/ she might be upset - probability

I could ride a bike when I was 5: general situation

I was able to ride a bike that stormy night: specific situation

In the negative couldn't is the same as wasn't able to

Could + have + past participle: Past ability that wasn't used, you had the opportunity but I didn't take it. You could have told me - (criticism)

May and might cannot be used in wh-questions

Obligation: from the speaker's point of view: Must - I must study for the exam (internal obligation, imposing myself) Have to- I have to study modals (I have to is external, somebody is obligating me to do that)

You mustn't use the dictionary - internal prohibition

Don't have to - Lack of obligation, you don't have to do it if you don't want to. To express an absence of necessity that is internal we use needn't /don't need to. NEEDN'T + have + past participle when the action happened but was unnecessary. We use MUST for strong recommendation and advice: you really must read this book its stunning - you must do something about your cough.

It can be very hot in the summer and He can behave quite rudely sometimes both sentences are correct because it's about general possibility. He can be fired soon is specific situation.

May be: probable situation - Might be less probable - could be there is a possibility but not sure - must have been I'm sure he did that - shouldn't have he did that and he was wrong criticized - can't incapable of doing something - Can't be Speaker is sure about something - may have it is probable - could have had the chance was not taken - can't have speaker is sure he didn't.

Might have been: it is probable

Must be: completely sure about something

Can't have been: speaker doesn't believe something

Could be: speaker believes that something is possible

Shouldn't have: criticizing something wrong

HAVE TO - MUST: Have to implies external obligation, somebody has to do something because an authority is forcing the person to do something

Must implies internal obligation. I feel the need to do something

Could / Was able to: could: have the ability to do something in the past and have the possibility of doing something - WAS able to: somebody had the opportunity once or overcome the situation by

Something you did unnecessary: I needn't have taken a sweater, it is very hot today

Criticizing: he shouldn't have told her what I said about him

Ability: Despite something, somebody was able to

Advice in a particular situation: you'd better do something

Refusal; you won't use my car

Unnecessary: I didn't need to take my car the meeting is just 1 block from home

He can't be married, he is too young

They might have decided not to come after all

Lets work out the details, shall we

She must have been very tired last night

it can be very hot here in summer

Shouldn't . moral obligation

Mustn't . Prohibition

Need and needn't modals

Don't need - do I need: semi-modals

Wh- questions can't be followed by may or might - who can or could help me - specific situation

Could- opportunity not taken

Can't be - certainty

Had better - prohibition

Adjectives: +ic - +al - +able - +ful - +ent - +ive -+ous -´ +less

Adjcs can sometimes act as nouns when they describe a particular group or characteristics OSASCOMP

-ED we use ed participles to describe a feeling that somebody experiences passive meaning

-ING We use participles to describe feelings or opinions, describe feelings that something causes