英语!关于 SHE'S 的含义 怎样判断是SHE IS 还是SHE HAS/?例子

后面直接接名词、代词形容词等的是she is 如she's a student
she has 后面接的是完成时态v-ed形式 如she's been to America twice那么这道题呢\he's already back to Australia, ( )?后面接的是isn't he 还是 hasn't he ...原因isn't he要是hasn't 的话back 前面要加beenV 是动词吧那SHE HAS NEVER BEEN TO .........这句话里就可以用HAS，但是BEEN在后面呀。。。。PS:could 用法she could hardly speak english 3 years ago这里的could是过去式还是语气委婉？？说实话，我一点都不明白你的意思，你上的句子he's already back to Australia根本就没有been， 而back又不作动词用，跟你的HAS NEVER BEEN，could hardly speak 有什么关系呢明白