Learn Turkish: Biz akşam köye dönüyoruz. - We are returning to the village in the evening.

The root word is köy (village). We add the dative case suffix -e to mean 'to' or 'towards' a place. It takes -e instead of -a because of vowel harmony: the only vowel in köy is ö, which is a front vowel.

Since the dative suffix uses a buffer 'y' after vowels, why is there no buffer letter in köye?

Unlike in English, the letter y is always a consonant in Turkish. Since the word köy ends in a consonant, it doesn't need a buffer letter to separate two vowels. We just attach the suffix -e directly.

Why doesn't akşam have a suffix like -da to mean 'in the evening'?

General times of day like akşam (evening) or sabah (morning) are usually used without any suffixes when we talk about when an action happens. Adding -da (in/at) isn't necessary here.

What are the different parts attached to the verb dönüyoruz?

The root is dön (return). To make the present continuous tense (like English '-ing'), we add -üyor. The ü is a connecting vowel chosen to match the ö in the root. Finally, -uz is the personal suffix for 'we' (biz).