This is the 19th most frequent Turkish word.
yeni
New.
In this sentence, 'yeni' is used as an adjective to describe the noun 'kitap' (book), indicating that the book is new.
Yeni bir kitap aldım.
I bought a new book.
Here, 'yeni' modifies the verb 'başladığımız' (we started), referring to something that has recently begun.
Yeni başladığımız projeye odaklanmalıyız.
We need to focus on the project we just started.
In this sentence, 'yeni' is used adverbially to indicate that the action of arriving has occurred recently.