This is a good place to study (in/on/at/x).

[kadioguy]

[My sentence]

This is a good place to study (in/on/at/x).

Technically, I think that a preposition is necessary.

Because We study [in/on/at] a place.

So "This is a good place to study [in/on/at]".

However, I guess that the preposition is practically optional. Is that right?

[Edit: Fixed a typo.]

 

[Cunning Fox]

Not a teacher nor a native speaker.

I'm afraid I don't understand you: first you say a preposition is necessary then you say it's optional. The preposition is indeed optional.
If I were held at gunpoint and had to choose one of them, I'd go for "in". Even though I can't quite come up with a context where the other two would work but I'd go ahead and assume it highly depends on what "place" refers to: is it a table or the top of a mountain? But it sounds far-fetched to me, so I'd stick to "in" (if I had to).

 

[kadioguy]

I'm afraid I don't understand you: first you say a preposition is necessary then you say it's optional.

Please notice the highlighting parts:

Technically, I think that a preposition is necessary.
[...]
However, I guess that the preposition is practically optional.

 

[emsr2d2]

Technical/grammatical points aside, in natural English we wouldn't use a preposition there.

 

[kadioguy]

Technical/grammatical points aside, in natural English we wouldn't use a preposition there.

How about this one?

This is a good classroom to study (in).

I assume that "in" is necessary here.

I suppose when the location is unspecific (like "a place") it is natural to omit the preposition, while the location is specific (like "a classroom") the preposition should be kept.

Is that right?

 

[jutfrank]

It's to do with the word 'place' itself. It sometimes kind of carries within it the meaning of the preposition. So we don't use a preposition at all when followed by a to-infinitive.

How about this one?

This is a good classroom to study (in).

I assume that "in" is necessary here.

Yes, because you've used classroom instead of place. Without the preposition, classroom is the object of study, which is not what you mean.