When the helper works with the child social interactions occur. Vygotsky thought that there are two important parts of social interaction: intersubjectivity and scaffolding. Intersubjectivity happens when two people start with different understandings. The two people interact with each other. By interacting, the two people get to the same understanding. Scaffolding happens when a teacher is helping a child. The teacher will change how much they help based on the child’s work level. The teacher will help more if the child needs it. The teacher will also help less if the child does not need help. Over time, the teacher lets the child work alone. When the child works alone he or she puts the conversation into his or her private speech. The private speech is then used to help the child do the problem.