I had studied English for eight years before I became a teacher

问题描述:

I had studied English for eight years before I became a teacher
had studied 理由 为什么用它

这是过去完成时 构成是 had +动词过去分词
表示过去某一时间之前就已经完成的动作
我成为教师 就是过去时了 在成为教师之前就学了八年英语 是典型的过去完成时
希望对你有所帮助,有不会的可以再问,