一.概念
连词是用来连接词,短语,从句或句子的词.连词不作成分.
二.重点连词
1.表示并列关系的连词有：and, both…and…, not only… but also…和neither…nor…等
1)and：和，并且（连接对等关系的字和字，句子和句子）
例如：i enjoy basketball , football and table tennis.
the weather becomes colder and colder.
2)both…and…既…也…,(两者)都…
注：both…and…构成的词组作主语时,谓语动词用复数。
例如：both jim and kate are from england.
both…and…否定句表示部分否定。
例如：you can’t speak both german and english.
both my father and my mother aren’t doctors.
3)neither…nor…:既不…也不…（就近原则）
例如：neither i nor he has seen the play before.
4)not only…but also…:不但…而且…（就近原则）
例如：not only the mother but also the children are ill.
2.表示转折关系的连词有：but, however, yet, still，while等。
例如：mary was a nice girl, but she had one shortcoming.
he was very tired, still he kept on walking.
3.表示选择关系的并列连词有：or, either…or…,whether… or…等。
1)or：或、否则
例如：is your friend english or american?
he doesn’t like dumplings or noodles.
祁使句后连接or ，表 “如果…,否则…”,有转折的意思，此时 or =if you don’t …,you’ll …
例如：hurry up, or you’ll be late.
=if you don’t hurry up, you’ll be late.
2)either…or…:或者…或者…; 不是…就是… (就近原则。)
例如：either you or i am right.
does either she or they like english?
注：由either…or…引导的否定句是完全否定。
例如：she isn’t either a student or a teacher.
3)whether…or…不管…还是…
例如：she is always cheerful, whether at home or at school.
4.表示因果关系的并列连词有：for(因为)，so(所以)。
例如：he is not at school today, for he has a bad cold.
it was late, so i went home.
5.引导时间状语从句的从属连词有：before, after, when, while, as, till, until, since, as soon as等。
例如：after they had planted their crops, they took a rest.
we have learned six lessons since he began to teach us.
注：1) when, while, as 都表示“当……时”
a. when 时间点，笼统时间段 when he was a young man
b. while 具体时间段，有始有终 while you are eating….
c. as 渐进渐变， as we become old…
例如：when i came in, my father was cooking.
while you are eating.
he sang as he walked.
2) not…..until, 译为“直到……才”。
例如：mr. green didn’t go to bed until his children came back. (格林先生直到他的孩子们回来才睡觉)
6. 引导条件状语从句的从属连词有：if(如果), unless(除非，如果……不)等。
例如：if you don’t go soon, you’ll be late.
=unless you go soon, you’ll be late.