連詞是一種虛詞， 它不能獨立擔任句子成分而只起連接詞與詞，短語與短語以及句與句的作用。連詞主要可分為兩類：并列連詞和從屬連詞。并列連詞用來連接平行的詞、詞組和分句。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。

并列連詞引導兩個并列的句子。

1)and 與or

判斷改錯：

(錯) They sat down and talk about something.

(錯) They started to dance and sang.

(錯) I saw two men sitting behind and whisper there.

(對) They sat down and talked about something.

(對) They started to dance and sing.

(對)I saw two men sitting behind and whispering there.

解析：

第一句： and 連接兩個并列的謂語，所以 talk 應改為 talked.

第二句：and 連接兩個并列的動詞不定式，第二個不定式往往省略to，因此sang 應改為 sing.

第三句：and 連接感觀動詞saw 后面的用作的賓補的兩個并列分詞結構，因此whisper應改為whispering.

注意：and 還可以和祈使句或名詞詞組連用表示條件。(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兩者都

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 關聯兩個分句時，一個分句因有否定詞not 而必須倒裝。

Not only does he like reading stories, but also he can even write some.

4)neithe…nor 意思為"既不……也不……"謂語動詞采用就近原則，與nor后的詞保持一致。

Neither you nor he is to blame.