Learn Turkish: Adam camı siliyor. - The man is wiping the window.

The word cam means glass or window. In this sentence, it is the direct object of the verb, meaning it is the thing being wiped. Because we are talking about a specific window (the window), we must add the definite accusative suffix. Using 4-way vowel harmony, the vowel 'a' in cam takes the -ı suffix, making it camı.

Could I just say Adam cam siliyor?

Yes, but it changes the meaning. Without the accusative suffix, cam becomes a general, indefinite object. Adam cam siliyor means 'The man is window-wiping' or 'The man is wiping a window' in general. Adding the -ı makes it camı, showing he is wiping a specific, known window.

Why is the verb suffix -iyor instead of -ıyor to match the suffix on camı?

Vowel harmony applies to each word individually based on its own vowels. The verb root is sil- (to wipe). Since its vowel is 'i', the present continuous suffix follows the 4-way harmony rule for 'i' and becomes -iyor, giving us siliyor. The word cam has the vowel 'a', so its suffix becomes -ı.

How is camı pronounced? Is it like 'kami'?