Want to apologise for being a nuisance. Have another question if I may. Here are two sentences from my grammar book:
Welcher Junge ist am stärksten?
Welcher Junge ist der stärkste?
Regarding the first one, could someone please tell me whether "am stärksten" is an adjective or an adverb in this context, and if the former is the case, then why is -en the inflection of choice here? And as for the second one, why is it "stärkste" and not "stärkster"?
The first means: "Which boy is strongest?" Superlatives used as predicative adjectives are always formed like this, with "am" and then the ending -en. Groß, größer, am größten. Klein, kleiner, am kleinsten. Wenig, weniger, am wenigsten. There are obviously (like almost always in natural languages) also irregularities: Viel, mehr, am meisten.
The second one means "Which boy is the strongest one?" The ending is -e and not -er because that is always how adjectival declensions work after definite articles, any table of adjectival declensions will tell you that.
