There are two sentences.
- I think it no use giving him money.
- I think it worth watching the movie.
Do the sentences above make sense?
I made these sentences myself.
There are two sentences.
Do the sentences above make sense?
I made these sentences myself.
Both sentences are correct as they stand - however, it would be more natural to include an 'is' (or more naturally when speaking, the contracted form 's), in the sentence. For example:
- I think it's no use giving him money.
- I think it's worth watching the movie.
With the second sentence (for me at least) it feels more natural to say:
- I think the movie is worth watching.
Both are grammatical, but rather literary: not many people would say them in ordinary speech today.
The basic structure is
X thinks Y [to be] Z
('to be' is optional) where Z is a description. "Think" here has the meaning of "judge" or "evaluate".
Your examples are related:
X thinks it Z
where Z is a more complicated description, which involves an action and perhaps an actor.
More commonly, "think" takes a finite "that" clause:
X thinks [that] Y is Z
The meaning of "think" here is a little wider: it can be judging or evaluating, but it can just express opinion or belief.
Why not use this:
- Giving him money is useless
or
- There's no use giving him money
/
- Watching this movie is pointless
or
- There's no point watching this movie
Makes better sense to a native English person and has a more perfunctory tone.
Stylistic note, you don't need to say, "I think", it is implied when you make this kind of a statement that it is your opinion.
Lots of native speakers use "I think", and there is nothing wrong with it from a grammar standpoint, but can weaken your argument and should generally be avoided.
If needed, you can always clarify later whether a statement is a fact or an opinion.