Was ist am besten?
"Was ist am besten?" = "What is the best?" Can I change "am" for the respective der, die or das? Why use am if it means = to the, at the, on the. :)
The short answer is no. :)
"am besten" is used to demonstrate a degree of comparison.
in this case the order goes: gut, besser, am besten for the positive, comparative, and superlative forms.
Positive: Äpfel sind gut. Apples are good. Comparative: Äpfel sind besser als Orangen. Apples are better than oranges Superaltive. Äpfel sind am besten. Apples are the best.
The same goes for other adjectives as well: see http://www.dartmouth.edu/~german/Grammatik/Comparatives/Comparatives.html
Great to know! As a follow up I was wondering how you would translate the English phrase "What is for the best?" in German?