Why is 「プールで人がいっぱいです。」 wrong?


[![enter image description
here](https://i.stack.imgur.com/ECeQz.png)](https://i.stack.imgur.com/ECeQz.png)

Anki deck gave me 「プールは人でいっぱいです。」

Why is it not 「プールで人がいっぱいです。」or 「プールで人をいっぱい」？

From my understanding, で marks the limitation where an action or state of
being takes place.

So wouldn't プールで mark the limitation as the pool, just like how
これは世界で一番おいしいラーメン has で marking the limit as the world?

人がいっぱいです marks the state of being as a lot of people?

I understand why 「プールは人でいっぱいです。」 works,

プールは as for the pool

人で limited to people

いっぱいです the state of "a lot"

So as opposed to other things like dolphins and cats of which there are not a
lot of, there are a lot of people at the pool.

But why doesn't 「プールで人がいっぱいです。」or「プールで人をいっぱい」work then?

What about 「プールは人がいっぱいです」or 「プールに人がいっぱいです」/「プールに人でいっぱいです」

教えてお願いします！

EDIT: IME kept changing いっぱい into 一杯 + clarified the question a bit w/ example
of 世界で.




First of all, いっぱい doesn’t refer to something people do. It's not an action.
It's not even a verb. It’s an adjective/adverb that describes a state where a
thing or place is full of something. So the use of で is incorrect to begin
with. に is a better choice than で because いっぱい means something exists in
abundance. When you state something exists in a particular place, you use に
with that place, not で.

In fact,

> プールに人がいっぱいいます。

is a valid sentence, whereas

> (*) プールで人がいっぱいいます。

is not.

いっぱい works in two ways, describing either of the following:

  1. the thing or place that is full of something (プール)
  2. the thing that is filling that thing or place (人)

In the first usage, the thing that is filling that thing or place takes the
particle で.

> 人でいっぱいです。

In the second usage, the same thing takes the subject’s spot with the subject
marker が.

> 人がいっぱいです。

So, singling out プール as a topic, we get the following two valid sentences.

> プールは人でいっぱいです。  
>  プールは人がいっぱいです。

As for other possibilities,

> プールに人がいっぱいです。

is OK, though it sounds a bit like a less proper, somewhat shortened, way of
saying

> プールに人がいっぱいいます。

The following sentence doesn’t work because it doesn’t say what’s full of
people. If it’s the pool that’s full of people, it should be used with either
が or は. There should be no place for に.

> (*) プールに人でいっぱいです。

None of the following, with 人を, works either, because people are not objects
of any action here. So there should be no place for を.

> (*) プールで人をいっぱいです。  
>  (*) プールは人をいっぱいです。  
>  (*) プールに人をいっぱいです。

By the way, when いっぱい doesn't mean one cupful or glassful of some liquid, it
is usually written in hiragana.

