“Reply” or “Response” are common ways to say “回复” in English.
If you’re looking for a more specific term, you could also use “answer” when referring to a response to a question. For example, “I received a reply to my email” or “Here is my response to your question” or “Thank you for your answer”.
These words can be used interchangeably in most contexts, but “reply” is often used when responding to a message or letter, “response” is a bit more general and can be used in various situations, and “answer” is typically used when directly addressing a question.
