从句(子句)是一组具有主语和谓语的相关单词。 子句与短语不同，因为短语是一组缺少主语或谓语或两者的相关单词。

形容词从句

形容词从句修饰名词或代词。 形容词从句几乎总是立即出现名词或代词之后。

要测试形容词从句，您可以提出几个问题。 哪一个？ 哪一种？ 大多数形容词从句都以"who," "whom," "which," or "that." Sometimes the word may be understood. The words "that" or "who," for example, might not specifically be in the sentence, but they could be implied. To determine the subject of a clause ask "who?" or "what?" and then insert the verb.

例:

• The book that is on the floor should be returned to the library.

偶尔，形容词从句通过相对副词引入，通常 "when," "where," or "why."

例:

• Home is the place where you relax.

副词从句

副词从句通常修饰动词，在这种情况下，他们可能会在一个句子出现在任何地方。 它们说明了为什么，在何种情况下，在何种条件下，或在何种程度上发生了行动或存在的情况。 与形容词从句不同，它们经常在句子中移动。

Example:

• When the timer rings, we know the cake is done. OR
• We know the cake is done when the timer rings.

副词从句始终以从属关系开头。 从属连词引入条款并表达与句子其余部分的关系。

名词性从句

名词从句不是修饰语，因此它们不是形容词和副词等下属，它们不能单独存在。 它们必须在另一种句型中起作用，总是作为名词。 名词从句用作介词的主语，主语补语，直接宾语或宾语。

名词从句通常以关系代词开头 "that," "which," "who," "whoever," "whomever," "whose," "what," and "whatsoever." 它也可以从属于连词开头 "how," "when," "where," "whether," and "why."

例:

• Whoever wins the game will play in the tournament.

sentence [´sentəns]   n.判决 vt.宣判；处刑   (初中英语单词)

insert [in´sə:t, ´insə:t]   vt.插入；夹入 n.插入物   (高中英语单词)

tournament [´tuənəmənt]   n.比赛，锦标赛   (高中英语单词)

clause [klɔ:z]   n.条(款)；分句，从句   (英语四级单词)