用完成式时，我的观念是
have+ been+pp 我已经...
have+ been+ving 我已经...(强调现在仍继续)
had + been+pp 我过去已经...(现在没有了)
had + been+ving 我过去已经...(过去仍再进行)
have+ been+pp 表被动
had + been+pp 表过去被动
上面应该没错吧

不就是“be able to”？

你在哪里看到Do you have learned....

Have you learned...还有最后那句话恐怕没有写完整。因为整个句子看起来是拿掉前件的past unreal conditional