Learn Turkish: Yazar duvara bakmaktan başka hiçbir şey yapmadı. - The writer did nothing but look at the wall.

The structure -mAktAn başka is used to say "other than doing" or "besides doing" an action. It combines the infinitive form of a verb like bakmak (to look) with the ablative case ending -tAn (from) and the postposition başka (other). Together, it literally means "other than looking."

Why does duvar (wall) take the dative ending to become duvara?

The verb bakmak requires the dative case, which shows direction. In English you look at something, but in Turkish you look to something. Therefore, the object of the looking action, duvar, takes the -a suffix.

Why is the negative verb yapmadı used when the English translation says "did nothing"?

Turkish uses double negatives to express concepts like "nothing" or "no one." The phrase hiçbir şey translates to "any one thing," so to say someone did nothing, you must pair it with a negative verb like yapmadı (did not do). Literally, it says "did not do any one thing."

Can we separate duvara and bakmaktan to change the word order?

No, because duvara is the direct target of the action bakmak. In Turkish, words tightly associated with an infinitive verb form a connected phrase. The block duvara bakmaktan functions as one unit meaning "from looking at the wall" and must stay grouped together.