英语中各种各样的条件句(11)

only if:
Only if a teacher has given permission is a student allowed to leave the room.
只有得到老师的允许，学生才能离开教室。
Only if the red light comes on is thereany danger to employees.
只有红灯亮了，员工才会有危险。
provided that/providing that:
I will agree to go provided/ providing (that) my expenses are paid.
如果帮我支付费用，我就同意去。
on condition that:
They agreed to lend us the car on condition that we returned it before the weekend.
他们同意借车给我们，条件是周末以前归还。
5. or 和 otherwise 经常可以表示条件
You’ve got to start studying, or you’ll fail all those exams.
你必须开始学习，否则你所有的考试都会不及格的。
解析：此句相当于 If you don’t start studying, you will fail the exams.
6. supposing 可以表示条件
Supposing you are wrong, what will you do then?
假设你错了，那你会怎么办？
Supposing he hadn’t recognised us – he might never have spoken to us.
假如他没认出我们来，他可能就不会和我们说话了。
八、口语中的条件句
在口语中，我们经常使用 i f从句而不使用主句，特别是在礼貌地要求人们做事时。If 通常后跟 will、would、can 或could，用于表示礼貌，例如：
If you would just sign here, please.