• why提问的句子，必须用because回答。 如： • -Why didn't he come yesterday? • -Because he was ill. • because的从句常放在主句之后。 • I missed the train because I got up late. • because不能与so连用。
Because
• • because+从句，because of+名词短语。
because引导的从句可用于强调句，其余不能。 如： • it's because he is kind that we like him.
•
because引导的从句可用作表语，其余则不能。 如： • This is because that the earth is traveling around the sun.
Adverbial Clause of Reason 原因状语从句
引导原因状语的从属连词：
• • • • • • • • because as since seeing (that) now (that) considering (that) in that ..ause，因为，表示直接的原因，语气最强。
• since可用于省略句，其余则不能。 如： • Since so, there is no more to be said.
Now that, Seeing that, Considering that, In that
• 都与since表示的意义相近，既然。 如： • Considering that everyone is here, let's begin our discussion.
• now that 用来说明一种新情况，然后加以推论。 如： • Now that you are ready, we'll start at once.
When
•
when 也可以引导原因状语从句，表示既然。 如： • I won't tell you when you don't want to listen.
For
• for，因为，是并列连词，它有时可表示因果关系 （只能放在主句之后）是对前面的分句进行解释， 只能表示附加或推断的理由。 如： • It rained last night, for the ground is wet this morning.
注意：
• 表示...的原因是因为...的时候，用the reason why...is that...而不是 the reason why...is because... 如： • The reason why I call you is that I miss you.
As
• as 因为，语气较弱，位置较灵活但一般放在主句 前，中间用逗号隔开，表示的是明显的原因。 如： • As he was not well, i decided to go there without him.
Since
• since，既然，一般放在主句前，中间用逗号隔开， 表示的是明显的原因或众所周知的事实。 如： • Since that this method doesn't work, let's try another.