Another form of modelling, recasts add or correct information without obstructing the natural flow of communication. The recast occurs when the facilitator modifies a learners utterance by adding new or different grammar (syntactic) or word meaning information (semantic) information. Think of it as the facilitator repeating the "right thing" or a "new thing."
Sample recast:
Student (using core board): "Want read"
Teacher: Oh, you want TO read.”
OR
"What do you want to read?”
(source: Robin Parker, PrAACtical AAC, 2012)
For more examples, see the full article: