because + clause
I stayed home because it was raining.
我呆在家因为下雨了。
因为；由于
由于或因为；因此；因为。；从已知、推断或确定的事实中得知。
for the reason that; since
由于或因为；因此；因为。
By or for the cause that; on this account that; for the reason that.
从已知、推断或确定的事实中得知。
As is known, inferred, or determined from the fact that.
She stayed home because she was sick.
她呆在家里因为她生病了。
用法提示：连词，引导原因状语从句
I passed the exam because I studied hard.
我通过了考试因为我努力学习。
用法提示：连词，引导原因状语从句
He is happy because his team won.
他很开心因为他的队赢了。
用法提示：连词，引导原因状语从句
I stayed home because it was raining.
我呆在家因为下雨了。
用于强调真正的原因。
I came not because I had to but because I wanted to.
我来不是因为必须来，而是因为想来。
多用于口语和一般书面语，引出原因时可与 because 互换；但 as 也能表时间“当……时”，需看上下文。
比 because 稍正式，常引导双方已知或既成事实的原因；也可表“自从”，需要注意区分。
作连词时较书面、文学化，引导原因通常放在主句之后并加逗号，日常口语少用。
grammar · medium
易错句子Because he was late, so he missed the bus.
正确表达Because he was late, he missed the bus.
中文可以说'因为...所以...'，但英语中'because'和'so'不能连用，保留一个即可。
grammar · medium
易错句子The reason is because he didn't study.
正确表达The reason is that he didn't study.
'reason is because' 是冗余表达，应使用 'reason is that' 或直接用 'because' 引导原因状语。
因为
He was late because of the traffic.
他因为交通堵塞迟到了。
仅仅因为
She loves him simply because he is kind.
她爱他仅仅因为他善良。
只是因为
Don't give up just because you failed once.
不要仅仅因为你失败了一次就放弃。
主要是因为
The trip was canceled mainly because of the weather.
旅行主要因为天气原因取消了。
部分是因为
He succeeded partly because of his hard work.
他成功部分是因为他的努力工作。
正因为
Precisely because it is difficult, it is worth doing.
正因为困难，才值得去做。
与“因为”直接相关，表示做某事的原因或理由。
表示因果关系中导致结果的原因。
说明或阐明原因。
表示结果，常与“因为”搭配使用。
询问原因，与“因为”在逻辑上对应。
因为，由于
The game was cancelled because of rain.
比赛因为下雨取消了。
仅仅因为；没有特别原因
I dyed my hair blue just because I felt like it.
我把头发染成蓝色只是因为我想这么做。
正因为如此
She forgot her keys, and because of that, she was late.
她忘了带钥匙，正因为如此，她迟到了。
因为我快乐
I sing because I'm happy.
我唱歌因为我快乐。
因为你值得
She bought the dress because she felt she was worth it.
她买了那条裙子因为她觉得自己值得。
Dictionary facts from DICTIONARY_API_DEV, ECDICT, WIKTIONARY.