英语动词的三单形式有那些?

动词的第三人称单数形式（简称单三式）
1．一般在词尾加“-s”help-helps make-makes ride-rides know-knows
2．在s z x sh ch 结尾的词在词尾加“-es”push-pushes pass-passes watch-watches wash-washes
3．以“元音字母＋y”结尾时,加“-s”；以“辅音字母＋y”结尾时,变 y为i,再加“-es”play-plays stay-stays study-studies carry-carries4．以“辅音字母＋o”结尾的词,多数在词尾加“-es”go-goes do-does
5．be动词的单三式为is 6．have动词的单三式为has
补充
:不定式的省略:Wil you join us?你要同我们一道去吗?
I should love to (join you).我愿意.
The boy wanted to ride his bicycle in the street but his mother told him not to.那个男孩想要到街道上骑自行车,但是他的妈妈叫他不要去.
Alice,why didn't you come yesterday?爱丽斯,你昨天为什么没来?
I was going to,but I had an unexpected visitor.我本来是要来的,但是家里突然来了一个客人.

过去式，现在式 将来式

be动词的单三式为is 过去式为was；have动词的单三式为has