1. sang → singing - and: cấu trúc song song
2. submitted → submit - and: cấu trúc song song
3. paid → pay - suggest that S + Vo
4. suggest → suggests - Peter số ít, everyday → HTĐ
5. to work → working ⇒ come → coming - suggest không đi với to-V
6. was → should be - was không có nghĩa, should be: nên có
7. is → should be - is không có nghĩa, should be: nên có
8. go → to go - suggest sb to do sth