Post #1694906

> “come in” (like answering a door knock) Not really for that. You would use 进来, 请进, or just 来/来来 in casual speech. The 来 derivative handles the invitation. 进去 marks movement into a space away from the speaker. It is for actual entry, not invitation. Eg: 胡同太窄, 救护车开不进去 (Hútòng tài zhǎi, jiùhùchē kāi bù jìnqu.) The lane is too narrow for the ambulance to drive in.