2. - When you are 100% sure100% sure, use MUST.
She must have a lot of money. She drives a
Ferrari.
- If you are not very surenot very sure, use MAY:
There’s someone outside, it may be John.
He hasn´t answered. He may not have seen
my message.
3. - If you are not sure at allnot sure at all, use MIGHT:
He might know the answer.
Real Madrid might win the Spanish league.
- If you are sure something is impossible/notsomething is impossible/not
truetrue, use CAN´T:
He can´t be ill. I saw him at a party last night.
