Use when to emphasize that you think it's definitely going to happen. If we see another zombie again I'm gonna lose my mind. When we arrive we'll need to check all the rooms for walkers. For example, as soon as he comes into the room I'll smash him in the head with this baseball bat. Use a past tense in the if clause often past simple tense and then you use wood in the other clause. Be careful don't put wood in theIf clause because if and would is never good except in some situations. With third conditionals here we are imagining an alternative past okay so it's not the real past but it's a hypothetical one. It looks like there