=> 1. I have written many letters. ( thì HTHT) 2. My father bought a refrigerator yesterday. ( thì QKĐ) 3. He has taught English at this school for 1 year. ( thì HTHT) 4. He is going to buy flowers to decorate his house. ( thì TL) 5. My mother will have made a shirt until my birthday. ( thì TLHT)
