Questions & Answers about Tek bir kitap alıyorum.
Why use tek bir instead of just bir?
While bir means "a" or "one", adding tek (single/only) emphasizes that you are buying exactly one book and no more. Together, tek bir translates nicely to "a single".
Why is kitap not in the accusative case (like kitabı)?
We only use the accusative case ending for specific, definite objects (like "the book"). Because you are talking about an indefinite object ("a single book"), kitap stays in its plain, dictionary form without any extra endings.
Does alıyorum mean "I am buying" or "I am taking"?
It can mean both! The verb almak is used for both taking and buying. You have to rely on context to know which one is meant. Here, either meaning works, but "buying" is very common when talking about items from a shop.
How is the word alıyorum built?
It comes from the verb root al (buy/take). We add the present continuous tense suffix -ıyor (meaning "-ing"), and finally the personal ending -um which stands for "I". Because of Turkish vowel harmony, the 'a' in al causes the suffix to use an undotted 'ı'.