Learn Turkish: Bu proje beni bunaltmaktan başka bir işe yaramadı. - This project served no purpose other than overwhelming me.

To say "other than doing something", you take the infinitive form of the verb (-mAk), add the ablative case suffix (-tAn or -dAn), and follow it with başka. Here, bunaltmak (to overwhelm) becomes bunaltmaktan başka (other than overwhelming).

Why is ben in the accusative case (beni) here?

Beni is the direct object of the verb bunaltmak (to overwhelm someone). Even though bunaltmak is embedded in an infinitive phrase, it still assigns the accusative case to its own object. The main verb of the sentence, yaramadı, does not affect this pronoun.

What does bir işe yaramadı mean literally, and how is the verb yaramak used?

Yaramak means "to be useful" or "to serve a purpose". The phrase bir işe yaramak is a common idiom meaning "to be of use". Literally, it translates to "to be useful for a job". Because yaramak requires the dative case for the thing being served, we use işe (to/for the job). In the negative past tense (yaramadı), it means "it served no purpose".

Could I say hiçbir işe yaramadı instead of bir işe yaramadı in this sentence?