There is one mistake in each sentence

there is one mistake in each sentence .Underline and correct the mistake

1. Nam is my classmates. He watches TV every night
2. I think collecting stamps are interesting
3. My dad cooks very good . He loves preparin​g meals for our family
4. I enjoy to ride my bike to school
5. We usually go in a small lake out of the city at weedkends
6. Do you still play football next year ?
7. We like doing fishing because it is relaxing
8. Do you think bird - watching interesting