怎么辨别因为是介词还是连词

because是介词时后接名词或名词词组，because是连词时接一个完整的句子。如Because of the rain,the sports meeting has been put off. Because it rains,the sports meeting has been put off.

because的用法

（1）because的基本意思是“因为”，强调直接造成某种结果的理由和原因，所引导的原因状语从句多置于主句之后，有时为了强调，也可置于主句之前，并用逗号与句子的其他部分隔开。

（2）because还可用来引导让步状语从句，这时，通常用于否定句或疑问句中。

（3）because有时还可引导表语从句。

because和because of的用法区别

一般句型结构为：

1.句子+because+句子

2.because+句子+句子

3.because of+名词/代词

从以上句型结构可以看出，Because是连词，连接两个句子，如：

1.I was worried because Mary was late.我很着急因为玛丽迟到了。

2.Because I was tired,I went home.因为我很累，我回家了。

Because of是复合介词，其后接名词、代词、动名词、what从句等。如：

I was late because of the rain.我因为下雨迟到了。

Because of之后可接 what 从句，但不能接that从句或没有引导词的句子。如：

He left the company because of what the boss said at the meeting.

他离开了这家公司，因为老板在会上讲的话。

He didn't come because of his illness.他因病没有来。