Would
1-. conditionnel
I would go to Nepal if I had time

I would buy a new car

 

Should
1-. Obligation atténué (devrais)
You should listen me
You should stop smoking

He should make more classes with me

We should meet tomorrow

2-. Quasi certitude
This road should lead us to the village

It should be all right!

You should learn English in 2 months

-. Exprime l'irritation ou un reproche
How should I know?
(should + participe passé)
You should have done that before
You should have told me

Can
1-. Toute possibilité lié au sujet
Can we do a class tomorrow?

Can you speak English?

Could
1-. Pouvoir au passé
You could speak english better before
They couldn't buy this house because they didn't have any money

2-. Question polie
Could I ask you something?
Could you find me this information?

3-. Conditionnel de "can"
I could go there
He could understand everything I said

 

Exemple de question anglaise avec COULD

 

Could you tell me how much it costs?

Could I use your phone?

Excuse me, could I have some information?

Could you send me confirmation?

Can I speak to Mr Dupont, please?

Can I leave him a message?

Could you give me your number, please?

Could I have a receipt, please?

Could I have a glass of water, please?

May I smoke here?

Could you get us some coffee please?

Could you call me back?

Could you give me a wake-up call at 7.30?

Could you speak up, please?

Could you help me?

Could you give me a hand?

Could you spell that, please?

Could you repeat that, please?

Could you speak more slowly, please?

Could we stop now, I'm getting a bit tired?

Could you translate in spanish?

Could I help you on any project?

Could you call me when you will be in Acapulco?

Could you give me 2000$ tomorrow?

Could you pay me what you owe me?

Could you tell me how old are you?

 
May
- Pas "s" à la troisième
- S'emploi comme auxiliaire
- Au futur (be allowed)

1-. Exprime la permission (possibilité extérieur au sujet)
People may smoke here
They may unfasten their seat belt. The sign has been turned off

2-. Exprime la posibilité - éventualité

- He may come late. Il se peut qu'il vienne tard.
- He may be on holiday. Il est peut-être en vacances.

3-. Souhait
May this year bring you happiness and health

4-. Question très polie
May I ask you something to drink?
 
Might
1-. exprime une possibilité au futur 50/50
I might go to Nepal in March