Make suggestions
1. Let's turn off faucet! (Hãy)
2. How about using bikes to go to school instead of motobikes? (Còn...thì sao)
3. Shall I take a shower instead of a bath? (Có nên)
4. Why don't we speak English with friends every day? (Tại sao chúng ta không...)
5. Why not do grammar exercise at home? (Tại sao không...)