很有意思的问题！其实我从来没有考虑好了。我试着解释： 我觉得主要区别是：“had been v-ing" 一般是 active voice. "had been v-ed" 一般是 passive voice. 比方说： l had been learning english for many years... He had been walking for a long time... The river had been flowing since March... 在这些例子中，the subject (I, he, the river)　都过去做着每个动词　(learning, walking, flowing)。 是active voice. 不过， "had been v-ed"　的意思是别人还是别的东西对 the subject 以前做了每个动词。 比方说： He had been killed... The keys had been lost... The cup had been filled... 都是passive, 有什么对Subject 发生了。有的时候句子包括谁完成动词：“The cup had been filled BY the boy." 但是我应该说我不是老师，还有真的不喜欢语法，可能解释错了！

I had been asked so many times how to say "solace," that I finally posted an answer on my page. I had been going to the store every day until I broke my foot. 第一个是：过了+别的事情过. 第二个是：多次过了，事情突然过，停着. I don't know if the Chinese is correct 我不知道如果我的中文解释是正确的. One thing HAD happened in the past, but then stopped. And one happened many times and then stopped.

Many cars had been repaired by George before he received his mechanic's license. I had been doing fine until he showed up, then I felt completely uncomfortable.