Point things out: これ, それ, あれ, どれ
The こ・そ・あ・ど pronoun system points to things based on distance: これ near the speaker, それ near the listener, あれ far from both, and どれ asks which.
Point things out: this, that, that over there, which one
これ or この?
Micro-Shiftこれは わたしのです。
Stands aloneThis is mine.
これ works like a noun on its own: “this one”. It can take は or を directly.
Japanese measures space from the two speakers. Words in こ (これ) belong to the speaker's sphere. Words in そ (それ) belong to the listener's sphere. Words in あ (あれ) sit far from both, where both must look away to see it. And words in ど (どれ) ask which one out of three or more.
These words stand entirely on their own as pronouns: これは ペンです (this is a pen), あれは なんですか (what is that over there?). They never attach directly in front of a noun (for that, use この, その, あの, どの).