非得 … 不可 (absolutely must)

Only he can do this

• (followed by a verb phrase…非得fēi děi + Action + cannot不可bù kě / won't do不行bù xíng / won't do不成bù chéng = "absolutely must / have to".
• this这zhèmatter事shì(followed by a verb phrase…非得fēi děi他来tā láicannot不可bù kě = "this absolutely has to be him."
• (followed by a verb phrase…非得fēi děi stresses there's no alternative.

(followed by a verb phrase…非得fēi děi + Action + cannot不可bù kě / won't do不行bù xíng / won't do不成bù chéng

• (followed by a verb phrase…非得fēi děi…cannot不可bù kě doubles down on necessity.

this这zhèmatter事shìabsolutely must非得fēi děihe他tācome来láino other way不可bù kě。

• (followed by a verb phrase…非得fēi děi他来tā láicannot不可bù kě = "it absolutely has to be him."

Recap

Read the full reference: HSK 6 grammar — Sentence patterns.