英语and的用法问题？

连词是一种虚词,它不能独立担任句子成分而只起连接词与词,短语与短语以及句与句的作用.连词主要可分为两类：并列连词和从属连词.并列连词用来连接平行的词、词组和分句.如：and,but,or,nor,so,therefore,yet,however,for,hence,as well as,both…and,not only…but also,either…or,neither…nor,(and)then等等.
并列连词引导两个并列的句子.
1)　and 与or
　判断改错：
　(错) They sat down and talk about something.
　(错) They started to dance and sang.
　(错) I saw two men sitting behind and whisper there.
　(对) They sat down and talked about something.
　(对) They started to dance and sing.
　(对)I saw two men sitting behind and whispering there.
解析：
第一句：and 连接两个并列的谓语,所以 talk 应改为 talked.
第二句：and 连接两个并列的动词不定式,第二个不定式往往省略to,因此sang 应改为 sing.
第三句：and 连接感观动词saw 后面的用作的宾补的两个并列分词结构,因此whisper应改为whispering.
注意：and 还可以和祈使句或名词词组连用表示条件.（or也有此用法）
Make up your mind,and you'll get the chance.
= If you make up your mind,you'll get the chance.
One more effort,and you'll succeed.
= If you make one more effort,you'll succeed.
2)　both …and　两者都
　She plays (both) the piano and the guitar.
3)　not only…but (also),as well as不但…而且）
　　　She plays not only the piano,but (also) the guitar.
注意：not only… but also 关联两个分句时,一个分句因有否定词not 而必须倒装.
Not only does he like reading stories,but also he can even write some.
　4)　neithe…nor 意思为"既不……也不……"谓语动词采用就近原则,与nor后的词保持一致.
　　　Neither you nor he is to blame.

都有可能。这要看and之后那个句子的意思和前面句子或者成分之间的关系了。
I know he is a teacher and I admire him. 我知道他是一个老师，并且我很欣赏他。（与主句并列）
I know he is a teacher and he works hard. 我知道他是一个老师并且工作很努力。（与从句并列）

and 是英语中的连词，它通常运用于并列句与递进转折句。并列句如：Jack ; Cathy; and I are the office worker. 递进转折句如：Music has played a part in the daily life of most people, and New Orleans is home to some of musicians.（音乐是多数人生活的一部分，而纽奥兰正是某些音乐爱好者的摇篮）。