We normally use would in the if-part of the sentence or after wish.

If I'd gone to the party last night, I ___________ lots of people.

Use the present perfect (I have done) when you talk about a finished time.

We use the continuous for things happening at or around the time of speaking. The action is  complete. 

My hands are very dirty. __________ my bike.

Police _______ two men in connection with the robbery. 

If we ______ by bus, it would be cheaper.

The house is dirty. They _______ it for weeks. 

lt ________for two hours.

When we imagine something that will not happen, or we

don't expect that it will happen, we use if+ past

(if we went I if there was I if you found etc.).