Adjunct relative clauses

Two types of trees to handle adjunct relative clauses exist in the XTAG grammar: one in which there is PP_w substitution with a null Comp built in and one in which there is a null NP_w built in and a Comp substitutes in. There is no NP_w substitution tree with a null Comp built in. This is because of the contrast between ((211)) and ((212)).

(210)0(210

(211)

the day [[on whose predecessor] [$\epsilon$_C [Muriel left]]]  (211)0(211

(212)

*the day [[whose predecessor] [$\epsilon$_C [Muriel left]]] 

In general, adjunct relatives are not possible with an overt NP_w. We do not consider ((213)) and ((214)) to be counterexamples to the above statements because we consider where and when to be exhaustive PPs that head a PP initial tree.

(212)0(212

(213)

the place [where [$\epsilon$_C [Muriel wrote her first book]]]  (213)0(213

(214)

the time [when [$\epsilon$_C [Muriel lived in Bryn Mawr]]]