How to use 莫非
Observation，莫非 + conjecture + (不成)？
莫非 introduces a possibility the speaker is considering, often because an observation calls for an explanation. The question may be a genuine conjecture or a rhetorical challenge to something the speaker finds surprising. English commonly uses could it be that. The expression can therefore carry uncertainty without always implying that the speaker already knows the answer.
Place 莫非 before the conjecture, either before its subject or after a subject that has already been introduced. An earlier clause often supplies the evidence prompting the guess. 不成 can appear at the end for additional rhetorical coloring. Distinguish a tentative explanation from a disbelieving challenge by reading the whole exchange and the speaker's tone.
Examples with pinyin and English
他今天没来，莫非生病了？
He did not come today. Could he be ill?
The first observation prompts the conjecture.
灯还亮着，莫非里面有人？
The light is still on. Could someone be inside?
莫非 introduces a possible explanation for the evidence.
莫非你已经知道答案了？
Could it be that you already know the answer?
The conjecture can form a complete question without 不成.
What to remember
- Give a clear observation behind the conjecture.
- Use 莫非 before the guessed explanation.
- Treat 不成 as optional rhetorical coloring.
Practise the pattern
Use one example as a model. Change the people, objects or situation, keeping the grammar pattern in the same order. Read the explanation again to check how your sentence uses the construction.
Look up the grammar words
Source and editorial notes
Explanation and examples written for Laowai using the grammar curriculum as a topic reference. The original curriculum credits AllSet Learning’s Chinese Grammar Wiki as used with permission. Read the retained source credits.
Difficulty labels describe the level of the explanation; they are not official HSK placement. Send a correction with this page’s URL.