When asked, "What are these called in English?" or similar, should we use just the right pronoun or can we also answer with the right demonstrative pronoun? For example, which is grammatical or preferred: "They are chopsticks" or "These are chopsticks"?
Both are possible, and grammatical, in Standard English. I might prefer going with "these are..." just to match the question. However, it is safe to say that when presented with a question like this, most people would typically produce the simple one-word answer "Chopsticks". In some dialects, or when aiming for an effect, I could go with "Them's chopsticks", but you should not use that in Standard English (unless aiming for said effect).
These, in common usage, seems to refer to something close at hand, where they're is most commonly used to refer to something more distant, in local or affiliation. Although these rules are broken occasionally. e.g."These N.Y. Yankees are a pain in the ass...they're breaking the spirit of the game, the way rich politicians are breaking the democratic system...."A Bostonian"