HSKReadyGet the appHSK 4 · Sentence types › Complex sentences › Alternative clauses
Using 不是……，就是…… to Present Alternatives
The paired pattern 不是……，就是…… links two alternatives. Depending on context, it can suggest that one of two possibilities is likely, that a repeated choice alternates, or that the alternatives cover the relevant possibilities.
他不是在图书馆学习，就是在家复习。
A guess or summary of the two relevant places where he studies.
Read the full explanation and examples
Meaning: presenting alternatives
The outline places 不是……，就是…… under selection compound sentences. It connects two clauses or phrases as alternatives: roughly, “either … or …” or “if it is not …, then it is ….” The first 不是 introduces one possibility; 就是 introduces the other. The pattern is useful when a speaker presents two plausible explanations, choices, or categories as the relevant options. The scope here follows the supplied HSK 4 outline point.
The relationship between the alternatives depends on context. They may be competing possibilities, as when someone guesses where a person is. They may describe a recurring choice, as when a group regularly chooses one of two activities. They may also divide the relevant cases into two categories. The pattern itself does not prove that the alternatives are logically exhaustive in every situation; the surrounding context supplies that implication.
他不是在图书馆学习，就是在家复习。
A guess or summary of the two relevant places where he studies.
周末我们不是去爬山，就是去看展览。
The sentence presents a recurring choice of activities.
Formation and sentence shape
Use 不是 before the first alternative and 就是 before the second. Each alternative should fit grammatically into the same sentence position. The two parts can be full clauses, verb phrases, or noun phrases. When they are clauses, keep their wording parallel where practical so that the alternatives are easy to compare. Do not add 或者 between the two parts; the paired markers already signal the choice.
她不是把钥匙放在家里了，就是放在办公室了。
The speaker presents home and the office as the two places to check for the keys.
Choosing the right situation
Use the construction when you want to frame two alternatives as the relevant possibilities, rather than simply list options. With a question or an uncertain situation, it can sound like a guess: the speaker thinks one of the two explanations is likely. In descriptions of habits or schedules, it can show a recurring choice. With categories, it can present a practical two-way division. It is not itself a question marker: whether the sentence asks something depends on its wording and context.
这家店的顾客不是附近的居民，就是来旅游的人。
The sentence divides the customers into two contextually relevant groups.
- For a guess, connect two plausible explanations or locations.
- For a recurring choice, use alternatives that genuinely repeat across occasions.
- For a category split, make the two groups clear in the surrounding context.
Contrast with 或者
或者 can also mean “or,” but it is a single conjunction that offers alternatives without the paired frame. Compare “我们周末去爬山或者看展览” (“We’ll go hiking or see an exhibition this weekend”) with the paired example above. The version with 不是……，就是…… gives the alternatives a stronger either-or framing and suits a speaker emphasizing the recurring or likely choice. The 或者 sentence is a neutral offer of options. Neither form is inherently incorrect; choose according to the relationship and emphasis you mean.
Frequently asked questions
Can I reverse the order of the two alternatives?
The order depends on how you want to frame the options. Put the first-mentioned possibility after 不是 and the paired alternative after 就是. Keep the sequence clear and natural for the context.
Does 不是……，就是…… make a sentence a question?
No. It marks a selection relationship, not a question by itself. A sentence can still function as a question if its wording and context make it one.
Does this pattern always mean that exactly two possibilities exist?
No. It presents two alternatives as relevant, but context determines whether they are intended to cover every possibility.
