About the structures verb+object+infinitive and verb+that

[Payton Campbell]

Hi!
I have a doubt.
1. He prefers her to be his assistant
Can I use a that clause to say the same?:
2. He prefers that she be his assistant?

What about the verbs insist and like?
Can I use these verbs with with both two forms: verb+object+infinitive and verb+that?

[Cerberus™]

I'd say both are possible with "to prefer".

"To insist" only with construction number 2.
"To like" only with number 1.

You used the subjunctive "be" after "that" in number 2, that is correct. You could also use "should + inf." instead. Either verb form is used when the main verb ("prefers") has potential influence on the outcome of the "that" clause.

That is not the case with "to like", so if you would use a "that" clause with it, you'd say "he likes the fact that she is (or "will be") his assistant".

If you intend to say that he has no influence on her becoming his assistant, you should not use the subjunctive after "prefers".