selectional restructions

selectional restrictions
 - the restrictions imposed by the predicates of the sentences above on their arguments
 - semantic phenomenon
 + there is no longer a reason to set up a separate mechanism in the grammar that handles them > grammar becomes more streamlined

selectional restrictions are restrictions on themantic roles

three levels of description
1 assigning functions to constituents
2 assigning categorial labels to them
3 assigning themantic roles to them

David         smashed          the window.
syntax         functional level         Subject       Predicator         Direct Object
                  form level                [S [NP N]    [VP [V             [NP Det. N ]]]
semantics                                  Agent           predicate         Patient

function and form are syntactically are syntactic notions while the themantic level of representation is semantic in nature