I won't go to the party unless I'm invited.除非我被邀请，否则我不会去参加晚会的。

I sleep with the window open unless its really cold.我总是开著窗户睡觉，除非天气非常冷才关上窗户。

Iron corrodes unless it is greased or kept clean.如果不涂油或保持清洁铁便会腐蚀。

Unless you work harder, you will not pass the examination.如果不加紧用功，你就不能通过考试。

Nothing could stop me from waiting for you to come back unless death.除了死亡再没有别的事物能够阻止我等待你回来。

You will fail unless you work hard.
如果你不努力工作,就会失败。

Unless he has any objections,we will carry out the plan.
除非他反对,否则我们就执行这项计划。

Let's have dinner out—unless you are too tired.
咱们出去吃饭吧——除非你太累了。

Substances have no tendency to expand unless (they are) heated.
除非受热,物质不会有膨胀的倾向。

I won't write unless he writes first.
除非他先写信,否则我就不写。

I will be very angry unless you have already spoken to her.
除非你已经对她说过了,否则我会很生气。

Don't ask me to explain unless you really don't understand.
不要叫我解释,除非你真的不懂。

Unless paying by credit card, please pay in cash.
如果不用信用卡付账,就请付现金。

unless所引导的条件状语从句常用一般现在时表示将来意义,主句多用一般将来时。unless在表示“除非”时,如其引导的从句谓语是be,而从句的主语跟主句的主语相同时,从句的主语和be就可省略。有时从句中主语为it时,也可省略it或从句中的有关成分。

在unless引导的肯定形式的条件从句中通常用肯定词,如:already, still, some, too。在unless引导的否定形式的条件从句中通常用否定词。

unless表示条件时后可接现在分词短语。

I won't go to the party unless I'm invited.除非我被邀请，否则我不会去参加晚会的。

I sleep with the window open unless its really cold.我总是开著窗户睡觉，除非天气非常冷才关上窗户。

Iron corrodes unless it is greased or kept clean.如果不涂油或保持清洁铁便会腐蚀。

Unless you work harder, you will not pass the examination.如果不加紧用功，你就不能通过考试。

Nothing could stop me from waiting for you to come back unless death.除了死亡再没有别的事物能够阻止我等待你回来。

You will fail unless you work hard.
如果你不努力工作,就会失败。

Unless he has any objections,we will carry out the plan.
除非他反对,否则我们就执行这项计划。

Let's have dinner out—unless you are too tired.
咱们出去吃饭吧——除非你太累了。

Substances have no tendency to expand unless (they are) heated.
除非受热,物质不会有膨胀的倾向。

I won't write unless he writes first.
除非他先写信,否则我就不写。

I will be very angry unless you have already spoken to her.
除非你已经对她说过了,否则我会很生气。

Don't ask me to explain unless you really don't understand.
不要叫我解释,除非你真的不懂。

Unless paying by credit card, please pay in cash.
如果不用信用卡付账,就请付现金。

• but但是
• worthless无价值的
• if not不然的话
• if是否
• except除了 ... 之外...
• save救
• without没有
• lest惟恐