Eight numbered pairs of sentences, each with two words in brackets and a small picture down the right. Tom has a dog, so his dog is big. Lily has a doll, so her doll is new. The child reads both sentences and circles the word that fits.
The first sentence always names the owner, which is what makes this the right sheet to start on. A child does not have to hold the whole rule in their head, they just have to notice who was mentioned and pick to match. His and her come first, then my, its, our, your and their arrive one at a time.
Two of the eight use its for an animal, the cat with its bed and the bird with its wings, which is the one most children hesitate over. Having only two options rather than six keeps that hesitation short.
Plain black on white and it downloads as a true vector PDF, so a class set costs very little in ink.