If you are trying to potty train a three-year-old but his grandmother has him one week per month and she doesn't encourage the potty training how do you show him what is right?

Stay on him at home consistently make sure he knows when to go and how to go don't let up on it prior to when he goes to stay with grandma just keep asking him what is he supposed to do when he needs to go to the bathroom and let him show you so you know that he knows how to do it himself. I would talk to the grandmother right off the hop! As an adult caring for your child, she also has a responsibility to ensure that your child is growing up properly, and that your parenting decisions are respected.If she does not wish to aid you in toilet training your child, ask her why!She may not want the chore, may be uncomfortable with the toilet training situation, or is unsure on how to handle it.Maybe she is showing you a passive/aggressive reaction..showing her dislike or antipathy for you by trying to undermine your efforts.If she does care for the child, then asking her about it may help bring it to a resolution. If she is hostile and insistent that she will not help you,or your child, then consider shortening or ending these week long visits.If she will not help you in such a common sense situation, then she is probably undermining you in other ways.