Relative Clauses

Features that are peculiar to the relative clause system are:
select-mode, possible values are ind, inf, ppart, ger
rel-pron, possible values are ppart, ger, adj-clause
rel-clause, possible values are +/- select-mode:
Comps are lexically specified for select-mode. In addition, the select-mode feature of a Comp is equated to the mode feature of its sister S node by the following equation:

(586)0(586

(587)

Comp.t:select-mode S_t.t:mode 

The lexical specifications of the Comps are shown below:

• _C, Comp.t:select-modeind/inf/ger/ppart
• that, Comp.t:select-modeind
• for, Comp.t:select-modeinf

rel-pron:
There are additional constraints on where the null Comp _C can occur. The null Comp is not permitted in cases of subject extraction unless there is an intervening clause or or the relative clause is a reduced relative (mode = ppart/ger). To model this paradigm, the feature rel-pron is used in conjunction with the following equations.

(587)0(587

(588)

S_r.t:rel-pron Comp.t:rel-pron  (588)0(588

(589)

S_r.b:rel-pron S_r.b:mode  (589)0(589

(590)

Comp.b:rel-pronppart/ger/adj-clause (for _C) 

The full set of the equations above is only present in Comp substitution trees involving subject extraction. So the following will not be ruled out.

(590)0(590

(591)

the toy [_i [_C [ Dafna likes t_i ]]]  

The feature mismatch induced by the above equations is not remedied by adjunction of just any S-adjunct because all other S-adjuncts are transparent to the rel-pron feature because of the following equation:

(591)0(591

(592)

S_m.b:rel-pron S_f.t:rel-pron 

rel-clause:
The XTAG analysis forces the adjunction of the determiner below the relative clause. This is done by using the rel-clause feature. The relevant equations are:

(592)0(592

(593)

On the root of the RC: NP_r.b:rel-clause   (593)0(593

(594)

On the foot node of the Determiner tree: NP_f.t:rel-clause