conj.因为；由于

I bought the house simply because it was large. 我购买了这房子，只是因为它面积大。

An argument was inevitable because they disliked each other so much. 争论是不可避免的，因为他们彼此非常厌恶。

I knew she was joking because she had a big grin on her face. 我知道她是在开玩笑，因为她脸上堆满笑容。

Many beautiful fish are fast disappearing because of the severe pollution. 因为污染严重，许多美丽的鱼类正在面临绝种。

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。

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。

because有时还可引导表语从句。

because可用于强调句。

not...because...结构有时否定主句，有时否定从句，须根据上下文正确判断。一般来说，否定主句时because前多有逗号，而如果because前有just，则多半否定从句。

because可用于省略句。