Beyler ne yapıyorsunuz???

What is en ve an

example giden gelen konuşan etc

but why I can´t use gidiyor geliyor konuşuyor instead of gıden gelen etc??

example

koşan kadım- running woman

why that??

The en/an suffix added to the verb stem creates an adjective or noun to describe the subject of a sentence.

Click here for an explanation from the Manisa Turkish website.

The woman is running = Kadın koşuyor.

The woman who was running fell. = Koşan kadın düştü.

Generally you use gidiyor/geliyor at the end of a sentence as a verb, to indicate an action. You generally find giden/gelen at the start of a sentence as an adjective to describe the subject, before the rest of the sentence finishes.