4.定语从句表示条件

具有条件状语功能的定语从句虽然在句子结构上用来修饰主句的主语、表语或宾语等，但实际上是用来说明主句中动作或状态发生的前提条件、假设或推测。此类从句既能用来表示真实条件也能表示同事实相违背或不可能实现的条件。也就是说，此类定语从句既可相当于一个真实条件状语从句，也可相当于一个非真实条件状语从句。将此类定语从句翻译为汉语时应加上连词“如果……就……”。

Many people，whose first language is not English，for example Spanish or Italian only need to study a few hundred hours to be able to speak English quite well．(人教大纲版高二上第34页)

许多人如果他们的第一语言不是英语，比如西班牙语或意大利语，那么他们就需要学习几百个小时才能讲好英语。

此句相当于Many people，if their first language is not English，for example Spanish or Italian，only need to study a few hundred hours to be able to speak English quite well．

Visitors who get tired of the sand and the sun can cool off in one of the many cafés，shops and restaurants on Copacabana's main avenue．(人教大纲版高二下第35页)

在科帕卡巴纳的主要大道两旁有许多咖啡馆、店铺和餐厅，游客们在沙滩上阳光下玩累了就可以到里边凉快一下。

Anyone who wants to enter the room must answer the question．(人教大纲版高一上第83页)

只要答出我的问题，你们就可以进入房间。

He that will not work shall not eat．

不劳动者不得食。

Anybody who saw the poor boy would have helped him．(=If anybody had seen the boy，they would have helped him．)

任何看见那个可怜的男孩的人都会去帮助他的。