Learn Turkish: Onun kırılgan vazosunu devireyazdım. - I almost knocked over his fragile vase.

It comes from the verb devirmek (to knock over or to topple). To form the "almost did" meaning, we take the root devir-, add the connecting vowel -e (based on vowel harmony), and then attach the approximative verb -yazmak. Finally, we add the past tense -dı and the first-person ending -m. The breakdown is: devir + e + yaz + dı + m.

Is devireyazdım commonly used in daily conversation?

Not really. The -(y)Ayazmak structure is quite literary and a bit old-fashioned. In modern, everyday spoken Turkish, people are much more likely to say az kalsın deviriyordum or neredeyse devirecektim (I almost knocked it over). However, you need to know this structure because it appears frequently in books and written texts.

Why does vazosunu end with what looks like a double suffix?

Because it contains both a possessive and an accusative marker. First, we add the third-person possessive suffix -su to vazo (vase), making vazosu (his/her vase). Since this specific vase is the direct object of the verb being knocked over, it needs the accusative case. We insert the buffer letter -n- and then the accusative suffix -u, resulting in vazosunu.

How is the adjective (fragile) built?