This is the 5th most frequent Afrikaans word.
wat
"What"
In this sentence, 'wat' is used as an interrogative pronoun to ask a question about the object of the action, 'what is being eaten'.
Wat eet jy vir aandete?
What are you eating for dinner?
Here, 'wat' is used as an interrogative pronoun within an indirect question regarding the subject of the verb 'think'.
Ek wil weet wat jy dink.
I want to know what you think.
Here, 'wat' is used as a relative pronoun introducing a descriptive clause about 'the book'.