"He is not capable of doing it."
Translation:Er ist nicht in der Lage, es zu tun.
Because zu (when it's required) goes immediately before the verb, just like in English to (when it's used) always goes immediately before the verb instead of in some random location (I want read the to book?) Here is an extended explanation of when infinitives need zu and when they don't.
Is it good German to say "Er ist dazu nicht fähig"? I've reported it, but interested to know if this has a different meaning, or Anwendung, than the model translation. Besten Dank!
Can someone please explain how one is to know in what position to place the "nicht".
Its basically the same, but it would be He can not do it. Now if theres any difference between He can not do it and He is not capable of doing it, it might be very minor.
not capable ("er ist nicht in der Lage..." or "er ist nicht fähig,...") is more like he lacks the ability to do it while "er kann es nicht machen" is more like he lacks the means of doing it.
Bismarck would say that, but nowadays this sounds oldfashioned. Youngsters might not understand you, on a university discussion on a social science topic someone might talk like that.
Er ist unfähig, es zu tun. ...nicht in der Lage = not in a position to...which is a different meaning!
Fähigkeit is a noun and has to be capitalised.
I'd use it with the definite article -- but even so, Er hat nicht die Fähigkeit, es zu tun sounds clumsy to me. "He does not have the capability to do it" is not as "clean" as "He is not able to do it".