6. Alice said to me that she had a headache yesterday.
7. Paul came in and said that he is really thirsty now.
8. Tim told me that he is going to call Sam.
9. Jane said that she can answer this question.
10. David said that John had already gone at six.

6: Alice said to me that she had had a headache the day before                                                                7: Paul came in and said that he was relly thristy then

8: Tim told me he was going to call Sam

9: Jane said that she could answer that question

10: David said Jonh had already gone at six 

( 4 câu đầu sử dụng câu tường thuật của các thì hiện tại đơn, hiện tại tiếp diễn, riêng câu 5 thì dùng thì quá khứ hoàn thành nên ko đổi khi chuyển sang tường thuật )