a. In clauses with time words: when, after, until, we often use the present tense forms to talk about the future. (e.g. I’ll come home when I finish work.) In conditional clauses with 'if' we often use the present tense forms to talk about the future. (e.g. We won’t be able to go out if it is raining.)
b. We do not normally use 'will' in clauses with 'if' or with time words. (e.g. I’ll come home when I finish work. (not when I will finish work))
c. but we can use will 'if' means a promise or offer. (e.g. I will be very happy if you will come to my party.)
d. imagine something: 'if + past' (if I found/ if I was/ if we didn't etc.) but meaning is not past. (e.g. What would you do if you won a million pounds? (we don't really expect this to happen.))
e. We do not normally use 'would' in the 'if-part' of the sentence. (e.g. I'd be very frightened if somebody pointed a gun at me. (not if somebody would point)) But you can use 'if ~ would' when you ask somebody to do something. (e.g., (from a formal letter) I would be grateful if you would let me know your decisions as soon as possible.)
f. In the other part of the sentence (not the if-part) we use would ('d)/ wouldn't. (e.g. If you took more exercise, you would (= you would) feel better)
g. ‘could’ and ‘might’ are also possible. (e.g. If you took more exercise, you might feel better. (= it is possible that you would feel better.)
h. Do not use when in sentences. (e.g. They'd be upset if I didn't go to their party. (not when I didn't go))
Idiom 365
Run out of Steam: to be completely out of energy or enthusiasm.
Example: The negotiation meeting is still carry on, they should be run out of steam already.