To avoid a better communication, it was necessary to increase
the common lexical knowledge; to reach this objective,
some knowledge topics of children daily experience were
explored. In this way the children plainly learnt the
basic lexicon and also some structures of "LIS".
A better and gradual acquisition of communicative knowledge
of "LIS" allowed all the children in the class to communicate
and to have a real, even if simple, relationship with
their deaf friend, both inside and outside the school.