非…不可【fēi…bùkě】

非…不可 says something must happen: there's no other way, or someone insists on it. The verb phrase sits between 非 and 不可. It works in speech and writing alike.

Necessity

With a situation or a task in view, it means there's no alternative.

Insisting

With a person as the subject and 要 after 非, it describes someone set on doing something, often against advice.

Bound to happen

About an outcome, usually a bad one, 非…不可 means "bound to".

Word order

不可 closes the pattern; it doesn't go in front of the verb. In speech it can be dropped after 非要 or 非得, but after plain 非 keep it.

• × 我非不可参加 → 我非参加不可
• × 我非参加 → 我非参加不可

不行 or 不成 can replace 不可 in speech. 非得…不可 has its own entry.