兩類被動句型的轉換

英語中有一種主動句可以轉換成兩種被動句型，它們通常是一些表示客觀說明的句子，如：

People believed that she is honest. 大家相信她是誠實的。

→ It’s believed that she is honest. 大家相信她是誠實的。

→ She is believed to be honest. 大家相信她是誠實的。

比較上面兩類被動句型可以發現，一類是“it+be+過去分詞+that從句”，另一類則是“主語+be+過去分詞+不定式”(其中的“主語”為前一類句型中that從句中的主語)，通常可用于這兩類被動句型的動詞有assume, believe, expect, fear, feel, know, presume, report, say, suppose, think, understand等，比較(同時注意其中時態和動詞形式的變化)：

It’s expected that he will come soon.= He is expected to come soon. 預計他很快就會來。

It’s expected that he has come. =He is expected to have come. 估計他會已經來了。

It’s known that is a good singer. =He is known to be a good singer. 大家知道他是位優秀的歌手。

It’s known that was a good singer. =He is known to have been a good singer. 大家知道他曾是位優秀的歌手。