    Sentence 1: Vygotsky's theory has been: the  wellspring. of our recent, appreciation of  the profoundly social nature of even very  young children's: imaginative: play'and, its  wide-ranging, infiuence..on;‘cognitive and.  Social development.    Sentence 2: Vygotsky's’: theory. ‘has, -had.  nothing.to do with our appreciation for the  social nature.of imaginative play in young  children.    