have always been willing to do 总是愿意做某事，

改写成had always done结构，要怎样写，

难道是have always would吗？

网友看看，自己提问了些什么问题？

1. 为什么要“改”？

2. 现在完成时改成过去完成时，能吗？

3. have always would 语法书上有这种形式吗？这叫什么时态？

have always been willing to do 总是愿意做某事，改写成had always done结构，要怎样写，难道是have always would吗？

    【答】These teachers have always been willing to help us since they came to our school. / These teachers had always been willing to help others before they came to our school.