* "Uit" - This is the most common antonym of "in" and translates to "out". For example, "Die boek is in die kas" (The book is in the cupboard) would become "Die boek is uit die kas" (The book is out of the cupboard).
* "Buite" - This translates to "outside" and is used when you're contrasting something being inside a space with being outside of it. For example, "Die kinders speel in die tuin" (The children are playing in the garden) could become "Die kinders speel buite" (The children are playing outside).
* "Op" - This translates to "on" and is used when you're contrasting something being inside something else with being on its surface. For example, "Die pen is in die sak" (The pen is in the bag) could become "Die pen is op die sak" (The pen is on the bag).
* "Aan" - This translates to "on" or "to" and is used when you're contrasting something being inside something else with being attached to it. For example, "Die prentjie is in die raam" (The picture is in the frame) could become "Die prentjie is aan die raam" (The picture is on the frame).
To determine the best antonym, you need to consider the specific context in which "in" is being used.