什麼是分裂句分裂句是以it為引導詞的強調句型。它的結構形式是：it + be的一定形式+中心成分+that-/who-分句。例如：It was Jane that / who called this morning.正是簡今天上午來電話了。It was a parcel that she brought him.她帶給他的是包裹。分裂句是由普通陳述句轉換而來的。透過這種結構可以強調除謂語動詞以外的大多數句子成分。例如：John gave Mary a handbag at Christmas.約翰在聖誕節給瑪麗一個手提包。根據上下文和語義意圖，說話人可以透過分裂句分別強調主語、間接賓語、直接賓語、狀語、使之成為資訊中心。例如：It was John that / who gave Mary a handbag at Christmas.正是約翰在聖誕節給了瑪麗一個手提包。It was Mary that John gave a handbag (to) at Christmas.是瑪麗在聖誕節得到了約翰給的手提包。It was a handbag that John gave Mary at Christmas.約翰在聖誕節給瑪麗的是一個手提包。It was at Christmas that John gave Mary a handbag.約翰是在聖誕節給瑪麗一個手提包的。分裂句的謂語動詞be還可以採取複雜形式。例如：It may have been at Christmas that John gave Mary a handbag.約翰可能是在聖誕節送給瑪麗一個手提包的。It might have been John who gave Mary a handbag.可能是約翰送給瑪麗一個手提包。分裂句可以強調多種多樣的狀語成分，例如強調時間狀語、地點狀語、方式狀語等。例如：It was when she was about to go to bed that the telephone rang.正是在她要去睡覺的時候，電話鈴響了。It was in Shanghai that I first met Philip.我是在上海第一次遇見菲利浦的。It was very reluctantly that she agreed to help.她非常勉強地同意幫忙。也可以強調由because 引導的原因狀語分句。例如：It was because he was badly ill that he delayed the work.正是由於他病得很厲害，他才延誤工作的。 主語補語通常不可以用作分裂句的中心成分，如在規範英語中通常不說：＊It is beautiful that she is.＊It is chairman of the Committee that he is.但是賓語補足語是可以這樣用的：It is chairman of the committee that they elected him.他們選他做的是委員會主席。It is green that they have painted the wall.他們已經把牆刷成的是綠色。