Questions & Answers about Onun boyu çok uzun.
Why is there a -u at the end of boyu?
The base word for "height" is boy. Since we are talking about "his" height, we need the 3rd person possessive suffix. Because boy ends in a consonant and its vowel is "o", 4-way vowel harmony tells us to add -u, making it boyu.
The current lesson mentions a buffer s for the possessive suffix. Why isn't it boysu?
The buffer s is only used when the noun itself ends in a vowel (for example, araba becomes arabası). Since boy ends in the consonant y, it doesn't need a buffer letter to separate two vowels. We just attach the -u directly.
Why doesn't the Turkish sentence just say O çok uzun (He is very tall)?
While O çok uzun is grammatically okay, Turkish speakers usually talk about physical height by saying someone's height is long, rather than the person themselves being long. So, "His height is very long" (Onun boyu çok uzun) is the most natural way to say "He is very tall."
Can I drop onun and just say Boyu çok uzun?
Yes, you can! Because the suffix -u on boyu already tells us it's "his" (or "her") height, the pronoun onun is optional. Including it just adds a little extra emphasis to make it clear exactly who you are talking about.