题目

some students in shanghai have had e-bags for several months
为什么用 have had

提问时间：2021-12-26

答案

本句使用的是现在完成时,现在完成时由"have+过去分词"构成.
现在完成时的使用有两种情况：
1.动作在说话之前已经完成,对说话当时已经产生影响,例如：
He has gone to Japan.(他已离开,产生的影响是他此时不在本地.)
I have had breakfast.(我吃过早餐,产生的影响是此时我不饿或者很饿,要看说话当时的情境或语境.)
2.状态在说话之前已经开始,持续到现在,或许还会持续下去.例如：
He has studied English for 5 years.("study English"的状态持续到现在,也许还在继续)
Now I have finished the work.("finish the work"的状态持续到现在,不再继续)
“Some students in shanghai have had e-bags for several months.”属于第二种情况,"have e-bags"这种状态到目前为止已经持续了一段时间“for several months",并且可能还在继续.