We use would (‘d) / wouldn’t when imagine a situation or action (= we think of something that is not real):
I would be nice to buy a new car, but we can’t afford it.
I’d love to live buy the ocean.
A : Should I tell Chris what happened?
B : No, I wouldn’t say anything. (= I wouldn’t say anything in your situation)
We use world have (done) when we imagine situations or actions in the past (= things that didn’t happen):
They helped us a lot. I don’t know what we would have done without their help.
I didn’t tell Sam what happened. He wouldn’t have been pleased.
Compare would (do) and would have (done):
I would call Sue, but I don’t have her number. (now)
I would have called Sue, but I didn’t have her number. (past)
I’m not going to invite them to the party. They wouldn’t come anyway.
I didn’t invite them to the party. They wouldn’t have come anyway.
We often use would in sentences with if:
I would call Sue if I had her number.
I would have called Sue If I’d had her number.
Compare will(‘ll) and would(‘d):
I’ll stay a little longer. I’ve got plenty of time.
I’d stay a little longer, but I really have to go now. (so I can’t stay longer)
I’ll call Sue. I’ve got her number.
I’d call Sue, but I don’t have her number. (so I can’t call her)
Sometimes would / wouldn’t is the past of will / won’t
|Tom : I’ll call you on Sunday. ->||Tom said he’d call me on Sunday.|
|Ann : I promise I won’t be late. ->||Ann promised that she wouldn’t be late.|
|Liz : Darn! The car won’t start. ->||Liz was annoyed because her car wouldn’t start|
Somebody wouldn’t do something = he / she refused to do it:
– I tried to warn him, but he wouldn’t listen to me. (= he refused to listen)
– The car wouldn’t start. (= it “refused” to start)
You can also use would when you talk about things that happened regularly in the past:
– When we were children, we lived by the ocean. In summer, if the weather was nice, we would all get up early and go for a swim.(= we did this regularly)
– Whenever Richard was angry, he would walk out of the room.
With this meaning, would is similar to used to:
– Whenever Richard was angry, he used to walk out of the room.