Asactivitycarried________asonethinksfitinone’ssparetime,leisurehasseveralfunctions.
Accordingtothe"principles-and-parameters"theory,"principles"refertohighlyabstractpropertiesofgrammarwhichareappliedtolanguageingeneralandwhichgeneratephrasesandatthesametimerestrainthepowerofMovea,while"parameters"allowgeneralprinciplestooperateincertainrestrictedways,accordingtowhichparticulargrammarsofnaturallanguagesvary.