Learn Turkish: O mankenler podyuma koşarak çıktı. - Those fashion models went out to the runway running.

It is formed by adding the suffix -arak to the verb root koş- (to run). This suffix tells us how the main action in the sentence was performed. In English, we usually translate it as "by running", "while running", or just "running".

Why is the suffix -arak used here instead of -erek?

It follows 2-way vowel harmony. Since the vowel in the verb root koş- is "o" (a back vowel), the suffix uses the back vowel "a", making it -arak. For a verb root with a front vowel like gül- (to laugh), it would be gülerek.

Why is it O mankenler and not Onlar mankenler for "Those models"?

In Turkish, demonstrative adjectives like "this" (bu) or "that/those" (o) never take the plural suffix when they are placed directly in front of a noun. You just use o, and the noun itself becomes plural (mankenler). You would only use onlar if it stands alone as a pronoun meaning "they" or "those".

I thought çıkmak meant "to exit". Why does it mean they went onto the runway here?