• Subject (of reporting verb) + reported verb (past tense) + that + original sentence (past tense, adjusted for pronouns and tense)

Here's the conversion for each sentence:

1. My friend said (that) they had moved into their new flat.
2. The teacher said (that) Tokyo was a densely populated city.
3. He said (that) his parents had already seen the film.
4. He told me (that) he knew exactly what she had done the day before.
5. He said (that) his sister was working then.
6. Tony said (that) he would help me with those exercises the following day.
7. She told me (that) she had been waiting for the bus when he arrived.
8. She said (that) she hadn't gone to the party.
9. They said (that) they had to see those movies that night.
10. My father told Ben (that) he was sure he had seen him there the week before.

1. My friend said that they had moved into their new flat.
2. The teacher said that Tokyo is a densely populated city.
3. He said that his parents had already seen that film.
4. He told me that he knew exactly what she had done the day before.
5. He said that his sister was working then.
6. Tony said that he would help me with those exercises the following day.
7. She told me that she had been waiting for the bus when he arrived.
8. She said that she hadn't gone to the party.
9. They said that they must see those movies that night.
10. My father told Ben that he was sure he had seen him there the previous week.