for表因为时怎么用?能用because或者becauseof代替吗?用法有什么区别?还有on表关于时该怎么用,与about有什么区别?

Question

for表因为时怎么用?
能用because 或者because of代替吗?用法有什么区别?
还有on表关于时该怎么用,与about有什么区别?

Answer 1

表原因时,
1）because语势最强,用来说明人所不知的原因,回答why提出的问题,because引导的是句子中的重要部分,常放在句末.逗号可加可不加.
例：You can trust those products because the quality never changes.
I haven”t been to the cinema lately,because I am too busy.
I didn”t go,because I was afraid.
2）当原因是显而易见的或已为人们所知,就用as或 since.since稍正式一些.
Since /As the weather is so bad,we have to delay our journey.
3） 由because引导的从句如果放在句末,且前面有逗号,则可以用for来代替.但如果不是说明直接原因,而是多种情况加以推断,就只能用for.
例：He is absent today,because / for he is ill.
He must be ill,for he is absent today.
because of后面应该加名词,这个具体句子中很好辨析．
例：I don't like him because of his dishonesty.
for表示原因时,置于主句之后,表示非直接的随后附加说明的理由或推断理由.
如：She didn’t go to school,for she was ill.
关于on和about：两者都可作介词,表示“关于”之意.在涉及文章、书籍、演说、报告等有关内容时,二者可通用.如：
a book on ／about the radio一本关于无线电的书
二者的区别在于：
on常用于较正式场合,着重指内容的严肃性、学术性及深度.一般指学术专著.如：
a report on the international situation关于国际形势的报告
We're going to listen to a lecture on African history this afternoon．今天下午我们将听（一个关于）非洲历史的演讲.
He'll give us a talk on the history of the Party．他将给我们做关于党史的报告.
about多用于口语中,表示的内容较为普通,是一般地提及的有关生活杂事、小事及人和物的.如：
The teacher will tell us a story about Edison．老师将给我们讲一个爱迪生的故事.
Did you read about it in the newspaper yesterday?关于此事你在昨天的报上看过了吗?