HSK 5 HSK V5
Correct

除非

/ chúfēi /
Strokes

Definition

only if (..., or otherwise, ...)/only when/only in the case that/unless

Example

As a Conjunction

only if; only when

1
Yào
xiǎng
rén
zhī
不知
  
,
chúfēiwéi
除非己莫为
  

Better not do it if you don't want others to know.

2
Chúfēi
除非
tiān
天气
fēicháng
非常
  
,
rán
不然
zǒngshì
总是
guān
zhāo
chuāng
shuìjiào
睡觉
  

He always sleeps with the window shut unless it's really hot.

3
Chúfēi
除非
dào
得到
shēng
医生
de
yǔn
允许
  
,
fǒu
否则
bìngrén
病人
可以
xiàchuáng
下床
zǒudòng
走动
  

Only if the doctor has given permission is a patient allowed to get about/around.

As a Preposition

except; but; short of

4
tái
chuáng
机床
chúfēi
除非
méi
rén
huì
kāi
  

No one can operate that machine tool except him.