This question nouns refers to nouns that are forms of verbs in English, or their equivalents in German.
Some examples are:
abholen: Abholung
anfangen: Anfang
aufnehmen: Aufnahme
The first one ends with -ung, and the second one ends with -ng, using its own "a," rather than a "u," as a vowel. That much I understand.
But the third ending "nahme," deviates significantly from the other two. If it followed the "pattern," it would be something like "aufnehmung," or "aufneng," but that's not the case.
Why is that? Is that for purposes of "assimilation?" Could it have to do with the "h" in "nehmen?" Is that the only deviation, or are there others that I haven't thought of?