1. Pete must stay at college after classes today; Must Pete stay at college after classes; Pete mustn’t stay at college after classes
2. He can speak English well; Can he speak English well; He can’t speak English well
3. We may ask the officer of the watch about it ; May we ask the officer of the watch about it; We mayn’t ask the officer of the watch about it
4. They must finish this work on Friday; Must they finish this work on Friday; They mustn’t finish this work on Friday
5. Mary can swim well; Can Mary swim well; Mary can’t swim well
6. We may came to see our teacher any time we like; May we came to see our teacher any time we like; We mayn’t came to see our teacher any time we like
7. Jack must learn to repair a transmitter this month; Must Jack learn to repair a transmitter this month; Jack mustn’t to repair a transmitter this month
8; He could play football well many years ago ; Could he play football well many year ago; He couldn’t play football well many years ago