Answer:
1. We mightn't have missed the train if we'd left home earlier.
2. Would you have known that was Susan if I hadn't told you?
3. She would have resigned from that job if she hadn't been promoted.
4. If I had worn my coat, I wouldn't have been so cold.
5. They would have gotten lost if a stranger hadn't shown them how to get there.
Explanation:
This activity concerns the use of the third conditional.
The third conditional is a structure used to talk about hypothetical situations in the past. The general structure is the following:
if + had/hadn't + past participle + would/could/might (not) + have + past participle
For example, suppose you went out yesterday and it started to rain. You got soaked from walking in the rain. Now, you will the third conditional to talk about a hypothetical event, an unrealistic past - a past in which you brought your umbrella with you, which did not happen:
If I had brought my umbrella, I wouldn't have gotten wet.
