Re: Sein and haben in German past tense
The origin of the perfect forms with "to have" is a much more interesting question...
I wonder if, for example in French, avoir (< L. habere) is used more or less like a place holder because I know the same auxiliary turns up in a reference to the future:
J'ai à chanter.
What makes it different from J'ai chanté is the form of the complement verb. I might go so far as to say that the auxiliary could have been anything, provided that it indicates the person and the number.
Does German also use haben as auxiliary for other tenses as well?
Always give as much context as you think unnecessary. How do you like your lamb leg steak? — Medium, right leg!