Could it be that…? (莫非)

Structure 莫非 + conjecture + （？／不成？）

莫非 (mòfēi) introduces a troubled conjecture about the likely cause of something puzzling: «could it be that…?, is it possible…?». The speaker already leans toward that explanation and floats it as a question. It keeps the literary reading 莫 (mò, «not») + 非 (fēi, «is not»), hence the double negative «isn't it that not…?» → «surely yes». It often closes with 不成 to reinforce the tone. The variant 莫不是 works the same and is folded in here.

Examples

他tā还hái没méi来lái，莫mò非fēi出chū了le什shén么me事shì？
He's still not here, could something have happened to him?
这zhè么me晚wǎn还hái不bù睡shuì，莫mò非fēi有yǒu心xīn事shì？
Still up so late, could something be on your mind?
莫mò非fēi我wǒ听tīng错cuò了le不bù成chéng？
Could it be that I heard it wrong?
灯dēng还hái亮liàng着zhe，莫mò非fēi他tā忘wàng了le关guān？
The light's still on, could he have forgotten to switch it off?

Levels are indicative: they follow the standard Chinese Grammar Wiki (AllSet Learning) progression, not an official HSK 3.0 mapping. We never assign levels by eye.

This point and the other 370, with audio on every example, inside Wanyu.