问题描述: Having conversations with friends doesn't help at all.为什么用doesn't不用isn't 1个回答 分类:英语 2014-10-27 问题解答: 我来补答 doesn't是助动词,后面要跟动词原形.而isn't是系动词,后面跟名词或动词加-ing.希望对你有用. 展开全文阅读