Modal verbs - 2

Possibility
Let’s learn about expressing possibility now. The verbs may, might and could show possibility now and in the future.
In this case, they have the same meaning. Look at this conversation.
Example:
A: My mother said that it may snow tomorrow.
B: Really? It might snow?! That’s great! I could make a snowman or go for a “snow” walk.
A: Don’t get too excited. If the temperature is high, it may not snow. It may rain.
B: Well, I guess I could still go for a walk in the rain.

Obligation and Advice
We can use verbs such as 'must' or 'should' to say when something is necessary or unnecessary, or to give advice.
Example:
- Children must do their homework.
- You should stop smoking.

To form past modals we use modal + have + past participle.