"Let's take this book."
Translation:Bu kitabı alalım.
The "bu" makes it a specific direct object. (It's not just any book, anymore; it's this particular book.) So it has to get the accusative ending.
Because "götürmek" means "take away" , "take " or carry: The man went out of his way to take me to the station. - Adam beni istasyona götürmek için zahmet etti.
I had to carry Harun upstairs. - Harun'u üst kata götürmek zorunda kaldım.
People say that you shouldn't put an i on a noun whenever there is bu; because it is already specified by bu. Well, what is this?!