Chinese grammar: Comparing 再zai and 又you

Both 再 (zài) and 又 (yòu) express the duplication of an action and can be roughly translated in English to "again". However, 再 is used to express actions that have not yet occurred (the "future again") and 又 is used for actions that have already occurred (the "past again"). They're not interchangeable.

再 is used to express repetition of an action in the future

再 is used to express something that has already happened and will happen again.

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Examples

再 can be used to say "another"

Aside from expressing the repetition of an action, 再 can also be used to express the equivalent of the English word "another".

Structure

Note that the "Object" mentioned above is usually also going to have an 一 and a measure word in front of it. You'll see that in the examples below.

Examples

再 can be used to say "and then"

再 can be used with 先 to express sequential order. (ex. Do this....and then this....) In some cases, 再 can appear by itself to simply mean "and then." While this doesn't sound so easy to confuse with 又, it's actually quite common for intermediate learners to misunderstand this use of 再 as meaning "again," so it's definitely worth mentioning here.

Structure

Examples

又 is used to express repetition of an action that has already occurred in the past

又 is used in declarative sentences and describes the simple repetition of actions. This repeated action has already occurred once in the past.

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Example

又 adds emotional coloring to events recurring in the future

又 is sometimes used to express that something that has happened before is going to happen in the immediate future. In this case, it usually appears with 要, 可以, 能, or 是. This usage often expresses exasperation or impatience with something happening yet again, but sometimes it's more neutral, or even happy.

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Example