NP  ::= Det CN ;
Det ::= Predets Quants ;

Predets ::= ;

Predets ::= "only" | "just" ;
Quants  ::= "this" | "my" | "one" | "the" | "a" | "every" | "some" ;

NP   ::= Detp CNp ;
Detp ::= Predet Quant Num ;

Predet ::= ;
Quant  ::= ;
Num    ::= ;

Predet ::= "all" | "only" | "just" ;

Quant ::= "these" | "my" | "many" | "some" ;

Num ::= "four" ;

CNp ::= "sons" ;
CN  ::= "son" ;

--