A. If Clause: 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. If clauses and hypotheses: use present tense forms after phrases like ‘what if’, ‘in case’ and ‘suppose’ to talk about the future if we think it is likely to happen. (e.g. Those steps are dangerous. Suppose someone has an accident.)
C. Wishes: We use past tense forms to talk about wishes: We use past tense modals ‘would’ and ‘could’ to talk about ‘wishes’ for the future. (e.g. I don’t like my work. I wish I could get a better job.)