Learn Turkish: Yeni proje komitece onaylandı. - The new project was approved by the committee.

Both mean 'by the committee' and are grammatically correct. In passive sentences, the suffix -ce or -ca is often used instead of tarafından to show who did the action. It is especially common in formal, official, or administrative contexts like decisions made by a committee.

How do we choose between -ce, -ca, -çe, or -ça for this suffix?

It follows standard two-way vowel harmony and consonant mutation rules. The word komite ends with the front vowel 'e', so the suffix needs an 'e'. Since the word ends in a vowel (which is voiced), the suffix starts with 'c' instead of the voiceless 'ç', resulting in -ce.

How exactly is the passive form built in the verb onaylandı?

It starts with the noun onay (approval). The suffix -la turns it into the verb onaylamak (to approve). Because this verb stem ends in a vowel, we use the passive suffix -n instead of -il or -ın, making it onaylanmak (to be approved). Finally, the past tense -dı is added.

Why isn't it yeni projeyi with an accusative suffix, since the project is the thing receiving the approval?