除非…否则【chúfēi…fǒuzé】

除非 names the one condition that would change things, and 否则 – "otherwise" – introduces what happens if that condition isn't met: "unless A, B". 不然 is the spoken alternative to 否则.

The 否则 clause describes the situation without the condition – usually something that won't happen or shouldn't. Read it as: only if A; if not A, then B.

Keep 否则

English "unless" carries the whole meaning in one word. In Chinese, the second clause needs 否则 or 不然. Without it the sentence becomes unclear, and can even read as "only if A, then B" – the opposite of what was meant.

• × 除非你快点儿，你会迟到 → 除非你快点儿，否则你会迟到

除非 at the end

Placed after the main clause, a 除非 clause works like English "unless" and needs no 否则.

除非…才, which states the condition positively ("only if A will B"), is covered with 除非 itself.