does 是do 的第三人称单数(he, she, it)形式, 即:He does , She does , It does 。当do (does)作实义动词时，意思是"做"。如: He does his homework every day.(他每天做作业。) 当 do(does) 作助动词时，无汉语实际意思。仅仅帮助动词做成疑问句或者否定句用。如: He does not do his homework. (他不做作业。) Does he do his homework? (他做作业吗？)