Will and can are used in the indicative: These actions are going to happen (will) or there is the real possibility they can happen (can). Would and could have different functions: Would: conditionals --- I would buy the car if I had the money. I would have bought the car if I had had the money. (etc.) Would: past habits When I was a child, my father would take us to the park every Saturday. Offers: Would you like some more wine? Could: Past ability: When I was in high school, I could run a mile in 14 minutes. Could: polite requests Could you help me with this math homework? vs. Can you help me...... Conditional: If I had a million dollars, I could buy you a new house.

Hello Friend : - Will - we say it when we are talking about present ( v1 ) - Would - we say it when we are talking about Past ( v2 ) can and could ,shall and should (( are the same )) and they called ( The Modals ) For example : 1. If i had enough money,i would help the poor people . ( Would ) 2. If i study well, i will get a good mark . ( Will ) And so on ....) thank you

"Will" means you are going to do something, whereas "would" indicates a desire to do something (but it is not definite). "Can" means you have the ability to do something, whereas "could" means there is a possibility of doing something. Hope this makes sense!