在英文中,我们可以用代词 that 和 this 来指前面整个句子所表达的意思。例如:

Peter was killed in the helicopter crash yesterday. That shocked all of us. (彼得昨天在直升机坠机中丧生。这让我们皆感震惊)
- 句中 that 是指 “Peter was killed in the helicopter crash yesterday.” 这整句。
The coffee machine is out of order. This is too bad. (咖啡机坏了。这太糟了)
- 句中 this 是指 “The coffee machine is out of order.” 这整句。

不过,我们亦可用关系代名词 which 来指前面整个句子所表达的意思。必须注意的是,这里只能使用 which 所引导的关系子句来修饰前面整个句子,不可使用其他关代。例如:

Peter was killed in the helicopter crash yesterday, which shocked all of us.
- 句中 which 是指 “Peter was killed in the helicopter crash yesterday.” 这整句。
The coffee machine is out of order, which is too bad.
- 句中 which 是指 “The coffee machine is out of order.” 这整句。

这种用法或结构经常出现在非正式口说英语中,但少见于正式的书写或写作。在书写时,which 的前面通常会加逗点来表示说话的停顿。口说时,有时就会在 which 关系子句的前面稍微停顿一下。例如:

Peter was killed in the helicopter crash yesterday, [停顿一下] which shocked all of us.
The coffee machine is out of order, [停顿一下] which is too bad.

当前面的句子是由一个以上独立子句所构成的合句(compound sentences)、或是由一个独立子句及至少一个从属子句所构成的复句(complex sentences)、甚至是由一个以上的独立子句及至少一个从属子句所构成的复合句(compound-complex sentences) 时,which 关系子句可能指整个合句、复句或复合句,亦可能仅指最后面的子句。另外,which 关系子句的前面通常会加逗点,但单独存在的情况亦所在多有。例如:

Paul usually came to work late so his boss fired him, which made him very angry. (保罗上班经常迟到,所以老板就把他开除了,这使他很生气)
- 句中 which 是指从属子句的 “his boss fired him” 这件事。
Paul hadn’t saved any money and just lost his job so he had to borrow some money from his friends, including Tom. Which was very unfortunate. (保罗之前没有存任何钱而且刚刚失业,所以他必须向包括汤姆在内的友人借钱。真是太不幸了)
- 句中 which 是指 “John hadn’t saved any money and just lost his job so he had to borrow some money from his friends, including Tom.” 整个复合句。

尽管上句中的关系子句 Which was very unfortunate. 系以独立子句的形式存在,不合文法,所以不会出现在写作中,但在口说中却很常见。在谈话时,第二位说话者经常使用这种指整个句子的 which 子句来评估第一位说话者所说的事情或表示意见。例如:

John: Paul has found a new job and promised himself to be on time to work every day. (约翰:保罗已找到新工作且保证每天准时上班)
Tom: Which is perfect because he can repay the money he borrowed from his friends, including me, at a later date. (汤姆:那好极了,因为日后他就可以偿还他向包括我在内的友人所借的钱)
- 句中 which 是指 “(Paul has) promised himself to be on time to work every day.”。