1) (Must/May) I stay in this room? –Yes you may. 2 (Can/ Should ) you speak louder? I( can’t/
shouldn’t ) hear you. 3) Tom, (may/ can) I use your bike?- I’m afraid, not. 4) You (must/ may)
help your parents in everything. 5). I (could/should) play football when I was ten. 6).You (can’t/
shouldn’t) eat so much if you want to be slim.