Learn Turkish: Usta aydınlanmaya kavuştu, sakinleşti ve yenilmez oldu. - The master attained enlightenment, calmed down, and became invincible.

The verb kavuşmak (to attain, to reach, or to reunite with) always requires its object to be in the dative case (-a / -e). Even though "enlightenment" acts like a direct object in English, Turkish treats it as a goal or destination you arrive to. Therefore, the verbal noun aydınlanma (enlightenment) takes the buffer -y- and the dative -a.

How is the verb sakinleşti (calmed down) constructed?

It is built from the adjective sakin (calm). The suffix -leş (or -laş) is a very common tool used to turn adjectives or nouns into verbs meaning "to become [adjective]." Here, sakinleşmek means "to become calm," and the -ti makes it simple past tense.

Can you break down the grammar behind yenilmez (invincible)?

The root is yenmek (to defeat or beat). Adding the passive suffix -il gives us yenilmek (to be defeated). Finally, -mez is the negative aorist suffix. In Turkish, the aorist is often used to form adjectives that describe a permanent or innate characteristic. So, yenilmez literally means "(one who) is generally not defeated," which is how Turkish expresses "invincible."