Rewriting modal verbs

Gap-fill exercise
By Nacho Montorio

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

1. It isn't a good idea to ski in summer clothes.
2. Don't jump in the water!
3. My brother doesn't know how to ride a bike.
My brother
4. Our advice for footballers is to wear leg guards.