Learn Dutch: Haal je het boekje uit de kast? - Are you getting the little book out of the closet?

The preposition uit means "out of" or "from" when you are taking something from inside a 3D or enclosed space, like a closet, a box, or a building. Since the book is inside the closet (kast), we use uit to take it out!

The translation says "getting", so why don't we use the verb krijgen?

In Dutch, krijgen means "to get" only in the sense of receiving something (like a present). When you mean "to get" as in fetching, grabbing, or taking something, you must use the verb halen.

Why is there a -je at the end of boek?

Adding -je turns it into a diminutive, meaning a "little book". As a handy grammar rule: whenever you see a noun ending in a diminutive like -je, it will always use het for "the", even if the original word used de!

Why does the sentence start with Haal instead of Je?

This is a yes/no question. To ask this type of question in Dutch, you swap the regular word order and put the verb (Haal) before the subject (je), just like we swap words to say "Are you" in English.