Learn Turkish: Her akşam hoca ile yazışıyoruz. - We message with the instructor every evening.

The root is yaz- (to write). We add the reciprocal suffix -ış, which adds the meaning of doing something mutually or 'with each other'. So, yazışmak means 'to write to each other', or 'to message'. Then we add -ıyor (present continuous) and -uz (we) to make it 'we are messaging'.

Why do we use ile here instead of just saying 'we message the instructor'?

Because yazışmak is a reciprocal verb (doing an action together with someone), it usually requires the postposition ile (with). In English you might just say 'message the instructor', but Turkish literally expresses this as 'we write mutually with the instructor'.

Could hoca ile be written as a single word?

Yes! The word ile (with) can be attached directly to the noun as a suffix. Since hoca ends in a vowel, you add a buffer y, making it hocayla. Both hoca ile and hocayla are perfectly correct and mean the same thing, though the attached suffix form is more common in spoken, everyday Turkish.

Why does the sentence use the present continuous tense (-ıyoruz) for something that happens her akşam (every evening)?