When do I use これ, それ, and あれ vs この, その, and あの to say "this" or "that".

example: why is it

> **それ** はペンです

vs

> **その** はペンです

?
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2016-06-11T07:22:37.383
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2020-12-28T04:29:26.907
2020-12-28T04:29:26.907
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question
usage demonstratives kosoado
Why/when should I use the different forms of this and that?
The choice depends on whether a noun is attached.

So このペン (this pen) is okay but これペン is not grammatical.  
Conversely これ (this) is okay but この is not grammatical.
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2016-06-11T07:31:04.157
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2016-06-11T07:31:04.157
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answer
これ・それ・あれ act as pronouns, while この・その・あの act as adjectives.

There is also the matter of spatial reference. これ・この refer to things close to
the speaker, それ・その refer to things close to the listener, and あれ・あの refer to
things away from the speaker and the listener.

Since この・その・あの act as adjectives, you must attach a noun to them. Since は is
not a noun, そのはペンです doesn't make sense. An example in which その makes sense
would be

> そのペンは新｛あたら｝しいです。

それはペンです makes sense, especially if it is a pen near the listener.
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2016-06-11T07:34:33.227
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2017-11-06T10:44:49.857
2017-11-06T10:44:49.857
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answer