You should reply to let the person who sent the invitation know whether or not you plan to go.

你应该回复，让发出邀请的人知道你是否打算去。

youdao

Conversations usually involve some sort of reply and response, where one person makes a statement or asks a question and the other responds based on what the first person said.

通常谈话将包括一些答复和响应，其中一个人给出陈述或提出问题，然后其他人根据第一个人所说的内容进行响应。

youdao

Specifya date / time-range (say, in 1-2 weeks) where the person can expect a reply.

记得告诉对方一个明确的日期或时间范围（比如，一到两周），让别人知道何时能收到答复。

youdao

"We had an advert in the Sunday Times last weekend and I have had one person reply so far, " he said.

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