Let Them Just 'Be' As Imaginary Friends Can Be Helpful
Your child will stop playing with make believe friends soon, mostly by first grade, when he starts playing with his school friends and realizes make believe friends are not socially acceptable. Till then fantasizing friends is normal and it serves as a medium to your child to be creative and imaginative at play. Also with so many changes happening in his world, this friend will be comforting for him.
It helps him to practice getting along with others as well initiate play.
Your child will create his own private world where he can express his different emotions to his invisible friend.
You get to know what your child thinks, his interests, etc. For instance, he may pretend play a classroom scene at home, where he uses the dining chairs for his imaginary friend to sit and teach him as a student while he pretends to be the teacher.