There's a simple test:
What are those?
A. Those are apples.
B. They are apples.
The answer key is B. This might just be a simple question, but I don't have a strong reason why A is not correct? Any thoughts? Thanks!
Word Choice – Why Use ‘They’ to Answer ‘What Are Those?’
word-choice
Best Answer
Both "Those are" and "They are" are grammatically possible, but "They are" is more likely.
"Those" is a demonstrative pronoun. It can be used to refer to an object that hasn't been mentioned before, by indicating it as "the ones distant from the speaker". "They" is a personal pronoun. It refers to an object that has already been mentioned.
"Those" can refer to objects that are distant from the speaker, but may be close to the listener. As such the reply could be "These are".
However there is no need to use a demonstrative pronoun to refer to something, as it has already been referred to by the first speaker. This means I can just use a personal pronoun to refer to "the same thing that you are talking about". When it is possible to use "they" it is preferable to using "those" as it avoids repetition.