一般情况下,直接在动词词尾+s ,例如：get→gets; take→takes
以s, sh, ch, x,结尾的动词,在词尾+ es,例如： teach→ teaches; fix→fixes; go→goes
以辅音字母加o结尾的单词,在词尾+ es,例如：go-goes ,do-does
以辅音字母+ y 结尾的动词,变y 为i,再+ es,如：study→ studies; try→tries
动词 have ,遇到主语是第三人称单数时,要用 has； 动词 be 的第三人称单数形式是is,was.
含有动词第三人称单数形式的句子变否定句时,要用 doesn't + 动词原形,如：
He goes to school at six in the morning. (变否定句)→ He doesn't go to school at six in the morning.
对含有动词第三人称单数形式的句子提问时,要用助动词 does,如：
She goes home at five every day. (对划线部分提问)→ When / What time does she go home every day?
情态动词没有人称变化,因此以下的情态动词三单不变
can-can
may-may
must-must
need-need
will-will
shall-shall
dare-dare
ought-ought