一般在祈使语气或go和come的不定式之后不再使用目的不定式。常用Go and find Bill(去把比尔找来)来代替Go to find Bill;用Come and talk to Ann(来跟安说说话)来代替Come to talk to Ann。即：两个祈使动词用and连接起来时可代替一个命令+目的不定式。
在一般情况下说：
I must go and help my mother.
我必须去帮助我母亲。
Ill come and check the accounts.
我将来清理账目。
而不是说：
I must go to help my mother.
Ill come to check the accounts.
即：用and连接两个不定式结构来代替不定式+目的不定式结构。(参见第246节Ⅰ。)
但如go和come用做动名词或以任何现在时态和过去时态出现时，应带一个表示目的的不定式：
Im thinking of going to look for mushrooms.
我想去采蘑菇。
I went to help my mother.
我去帮助母亲了。
Ive come to check the accounts.
我来查账来了。
I didnt come to talk to Bill;I came to talk to you.
我不是来跟比尔说话的;我是来跟你说话的。