Learn Turkish: Pazarlama yapmadıklarından dolayı satışlarda artış görmediler. - They did not see an increase in sales because they did not do marketing.

This is the core of this lesson's structure. Let's break it down: yap (do) + ma (negative) + dık (verbal noun suffix) + ları (their, matching the "they" subject) + n (buffer) + dan (ablative case). Together with the postposition dolayı, it literally means "due to their not doing". The -dık suffix turns the verb into a noun-like clause so it can take possessive and case endings.

Is dolayı absolutely necessary in this sentence?

No, you can drop dolayı and just use yapmadıklarından. The ablative suffix -dan attached to a -dık clause already carries the meaning of "because of" or "from". Adding dolayı simply emphasizes the causal relationship, much like saying "due to the fact that" instead of just "because".

Why is satışlarda used instead of a direct object like satışları?

This relates to how the noun phrase is constructed. They didn't see the sales themselves; they saw an "increase" (artış). In Turkish, an increase happens in or at something, so we use the locative case -da. Therefore, satışlarda artış means "an increase in sales".

What kind of word is artış and how is it formed?