Question

1. I believe him to be sincere.
2. I believe him to go there.

3. I imagine him to be sincere.
4. I imagine him to go there.

5. I guess him to be sincere.
6. I guess him to go there.

7. I suppose him to be sincere.
8. I suppose him to go there.

9. I think him to be sincere.
10. I think him to go there.

11. I consider him to be sincere.
12. I consider him to go there.
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Are they all geamatical? Can we delete 'to be'?

Answer 1

2, 4, 6, 8, 10, and 12 are not correct. These infinitives all need to be "to be" infinitives, not action verb infinitives.

The other sentences are correct. I wouldn't delete "to be."