Use may/ might/ must/ mustn’t or needn’t.

You … ring the bell. I have a key.

• might

• needn’t

• may

• need

We … drive fast. There is a speed limit here.

• mustn’t

• needn’t

• might

• mustn’t

You … find you have made a mistake.

• must

• may

• needn’t

• need

Accept his offer now. He … change his mind later.

• need

• may

• might

• must

We … drive fast. We have plenty of time.

• mustn’t

• might

• must

• needn’t

We … make any noise or we’ll wake the baby up.

• must

• Need

• mustn’t

• might

You … do all the exercises. They are very important.

• might

• must

• need

• may

I want this letter typed but you … do it today. Tomorrow will do.

• needn’t

• mustn’t

• may

• might

You … take anything out of a shop without paying for it.

• must

• mustn’t

• need

• might

Ask your bank manager. He … be able to advise you better than I can.

• might

• need

• may

• must