Let him have a day off and find a replacement
When a child is little, they must have a ton of interaction with other people. Children repeat things they hear when they're little, and with the caregiver not communicating with the child, they don't have a chance to engage the brain through words. With the caretaker not using the child's name, the babe might not respond when people call their name, which is not good. With no walking or crawling, the baby will have a hard time learning as it isn't practicing when it counts the most.
