Nicaraguan Sign Language
The staff of the school missed the fact that a language was developing before their eyes. All they saw were some mimics, and the failure to learn Spanish. As they did not know what the pupils were saying, they asked for help. In 1986, Judi Kegl, an expert on the topic of American Sign Language was asked to help. When she analysed the language, she found out that the pidgin NSL had been made more complex by the younger pupils — it now included a fixed grammar, and the arrangement of verbs. Today, this extended form is known as ISN.