作为助动词的do和does是没有词义的, 它们在句中的构成一般现在时的疑问句和否定 句.Do用于主语第一人称,第二人称和第三人称 复数形式的句中,does用于主语第三人称单数 的句中。 ? We don't like bananas. (do not=don’t) ? Do you like apples? ? Does he like English? ? He doesn't like swimming. ? 上面有一句He does his homework in the evening. 要是变成否定句就成了这个样子: ? He doesn't do his homework in the evening. 这里加上了助动词doesn't,而原来的主动词 does变成原形do了。