为什么英语的句子前面加'and'....告诉下.谢谢了。.(详细点)

and 作为连接词，可以表示对话题的补充说明，或进一步解释。有时候可以省略。

I have finished the work, and I want my payment now.
我已经完成工作了，现在就要工钱。

I had made a mistake, and I feel soory indeed.
我弄错了，而且感到很抱歉。

Please give me feed back as soon as possible, and that is an urgency!
请尽快给我答复，这很紧急。

连词 conj. 和；加
together with;joined to;added to
· Look at that horse and cart.
瞧那匹马和马车。
· My father and mother are school teachers.
我的父亲和母亲都是学校老师。
· Two and two are four.
二加二等于四。

连词 conj. 连接两个动词
connecting two verbs
· We danced and sang.
我们又跳舞又唱歌。

连词 conj. 连接句子
connecting sentences
· He came and then he went.
他来了而后又走了。

连词 conj. 表示结果
showing a consequence
· He stood up, and all were silent.
他站了起来，于是大家都静了下来。
· Say that again and I'll hit you.
你要再说一遍，我就揍你。

连词 conj. 与‘去、来、送’等词连用表示目的