在英文中，我們可以用代名詞 that 和 this 來指前面整個句子所表達的意思。例如：
- Peter was killed in the helicopter crash yesterday. That shocked all of us. (彼得昨天在直昇機墜機中喪生。這讓我們皆感震驚)
－ 句中 that 是指 “Peter was killed in the helicopter crash yesterday.” 這整句。 - The coffee machine is out of order. This is too bad. (咖啡機壞了。這太糟了)
－ 句中 this 是指 “The coffee machine is out of order.” 這整句。
不過，我們亦可用關係代名詞 which 來指前面整個句子所表達的意思。必須注意的是，這裡只能使用 which 所引導的關係子句來修飾前面整個句子，不可使用其他關代。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.” 這整句。 - The coffee machine is out of order, which is too bad.
－ 句中 which 是指 “The coffee machine is out of order.” 這整句。
這種用法或結構經常出現在非正式口說英語中，但少見於正式的書寫或寫作。在書寫時，which 的前面通常會加逗點來表示說話的停頓。口說時，有時就會在 which 關係子句的前面稍微停頓一下。例如：
- Peter was killed in the helicopter crash yesterday, [停頓一下] which shocked all of us.
- The coffee machine is out of order, [停頓一下] which is too bad.
當前面的句子是由一個以上獨立子句所構成的合句 (compound sentences)、或是由一個獨立子句及至少一個從屬子句所構成的複句 (complex sentences)、甚至是由一個以上的獨立子句及至少一個從屬子句所構成的複合句 (compound-complex sentences) 時，which 關係子句可能指整個合句、複句或複合句，亦可能僅指最後面的子句。另外，which 關係子句的前面通常會加逗點，但單獨存在的情況亦所在多有。例如：
- Paul usually came to work late so his boss fired him, which made him very angry. (保羅上班經常遲到，所以老闆就把他開除了，這使他很生氣)
－ 句中 which 是指從屬子句的 “his boss fired him” 這件事。 - 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. (保羅之前沒有存任何錢而且剛剛失業，所以他必須向包括湯姆在內的友人借錢。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.” 整個複合句。
儘管上句中的關係子句 Which was very unfortunate. 係以獨立子句的形式存在，不合文法，所以不會出現在寫作中，但在口說中卻很常見。在談話時，第二位說話者經常使用這種指整個句子的 which 子句來評估第一位說話者所說的事情或表示意見。例如：
- John: Paul has found a new job and promised himself to be on time to work every day. (約翰：保羅已找到新工作且保證每天準時上班)
Tom: Which is perfect because he can repay the money he borrowed from his friends, including me, at a later date. (湯姆：那好極了，因為日後他就可以償還他向包括我在內的友人所借的錢)
－ 句中 which 是指 “(Paul has) promised himself to be on time to work every day.”。