subjunctive modals
I have a question about certain verb tenses of modals, both in the indicative and subjunctive.
I found the following construction:
"Ich konnte das gemacht haben."
Question #1: How is that different in meaning than "Ich habe das machen können."? Wouldn't both constructions mean "I was able to have done that."? Do they differ significantly in meaning?
My second question is whether this construction could also be used with modal verbs. For instance, would this sentence construction be valid?:
"Ich könnte das gemacht haben." Would that be the same in meaning as "Ich hätte das machen können"?
Danke im Voraus!
Adam