Нужно поставить "to".
Я примерно поставил, но мне нужно, чтобы правильно было.

1. You have TO take part in the competition.

2. Let me know when you are free.

3. I'm going TO see the new play at our theatre.

4. We decided not TO go out because of the weather.

5 I saw children cross the street.

6.What made you  think so?

7. But you didn't ask me.

8. We want you TO join our expedition

Объяснение:

1.to

2.

3.to

4.to

5.

6.

7.

8.to

Вы все правильно поставили