Questions & Answers about Bu on üç kitap yeni.
How do you form the number on üç (thirteen) in Turkish?
In Turkish, you build numbers from 11 to 19 simply by putting the word for ten (on) followed by the single digit. So, on (ten) and üç (three) gives you on üç (thirteen). Notice that they are written as two separate words.
Since there are thirteen books, why isn't the word for book plural (kitaplar)?
In Turkish, a noun that comes directly after a number is always singular. Because the number (on üç) already tells us there is more than one, adding a plural ending to kitap is considered repetitive. It is always on üç kitap, never on üç kitaplar.
The English translation says "These thirteen books", so why does the sentence use Bu (this) instead of Bunlar (these)?
When a pointing word like Bu is used to describe a noun right next to it, it never takes a plural ending in Turkish, even if the noun phrase is plural. You only use Bunlar when it stands completely alone, like in Bunlar yeni (These are new).
Where is the verb "are" in the sentence Bu on üç kitap yeni?
There isn't one! In Turkish, for simple statements meaning "is" or "are" in the third person (he/she/it/they), you often don't need a separate verb. You just put the subject (Bu on üç kitap) and the describing word (yeni) next to each other.