Questions & Answers about Uyumak, beyin için çok iyi.
Why does this sentence use the full infinitive uyumak instead of the short -mA form we're learning in this lesson?
Because this is a general statement: "Sleeping is good." When talking about an action in general, you use the full dictionary form -mAk (or -mek). The short form (-mA) is used when you need to attach a personal possessive ending, like in uyumam lazım (I need to sleep / literally "my sleeping is necessary"). Since no one specifically owns the sleeping in this general sentence, it stays as uyumak.
Why is there a comma after uyumak?
In Turkish, a comma is frequently used right after the subject of a sentence to prevent confusion and show exactly what the subject is. This is especially common in "to be" sentences like this one that don't have a visible action verb at the very end to give us context clues.
Why is it beyin için rather than using an ending like beynin için?
The word için (for) directly follows plain nouns. It only requires the genitive case (like the -in ending) when used with personal pronouns, such as benim için (for me) or senin için (for you). Since beyin (brain) is a regular noun, it doesn't take an ending before için.
I remember some body parts change their spelling. Would beyin change if we added a suffix to it?