unless
conjunction
ʌnˈles conjunction
1 used to say that something will happen or be true if something else does not happen or is not true 如果不…，除非…
Unless some extra money is found, the theatre will close.
要是不能额外弄一些钱，剧院将要关闭。
I think you should complain – unless, of course, you are happy with the way things are.
我觉得你应该发发牢骚 — 当然，除非你对现状很满意。
He won’t go to sleep unless you tell him a story.
要是你不给他讲故事他就不睡觉。
I can’t leave her unless I know she’s all right.
除非我知道她没事, 否则我不能离开她。
2
not unless
only if 只有…
‘Will you go with her?’ ‘Not unless she wants me to.’
“你和她一起去吗？”“只有她想让我去我才去。”
3
unless
Use to say that something will happen or be true if something else does not happen or is not true. 表示某事将会在另一事不发生或不真实的情况下发生或成为事实，用 unless
Unless they get protection, they will not testify.
如果得不到保护，他们不会作证的。
4
unless
Do not use the future tense after . unless后面不要用将来时
I won’t go unless you go (NOT 不说 unless you will go) .
你不去的话我也不去。
5 Do not say ‘unless if’. 不要说 unless if
Don’t call him unless it’s urgent (NOT 不说 unless if it’s urgent) .
事情不紧急就别给他打电话。
6
If ... not
Use when you know that something did not or will not happen. 如果你知道某事没有发生或不会发生，用 if ... not
If he had not tripped, he would have won (=but he didn’t win) .
他如果不是绊倒了，就赢了。
I would go out if it wasn’t raining (=but it is raining, so I am not going out) .
要是不下雨我就出去了。
7
in case
Use when talking about something that is or should be done because something might happen. 表示因为某事有可能发生而做或应该做另一件事，用 in case
Take a sweater in case you get cold (NOT 不说 unless you get cold) .
带一件毛衣，以防你会冷。
8
or or else
Use or to say what bad thing will definitely happen if something else does not happen. 表示如果不做另外一件事，某件不好的事肯定会发生，用 or 或 or else
You’d better go, or else you’ll miss the train (NOT 不说 unless you miss tha train) .
你该走了，否则会赶不上火车的。