Relative Clauses

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

(532)0(532

(533)

Comp.t:$\langle$select-mode$\rangle =$ S_t.t:$\langle$mode$\rangle$ 

The lexical specifications of the Comps are shown below:

• $\epsilon$_C, Comp.t:$\langle$select-mode$\rangle =$ind/inf/ger/ppart
• that, Comp.t:$\langle$select-mode$\rangle =$ind
• for, Comp.t:$\langle$select-mode$\rangle =$inf

$\langle$rel-pron$\rangle$:
There are additional constraints on where the null Comp $\epsilon$_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 $\langle$rel-pron$\rangle$ is used in conjunction with the following equations.

(533)0(533

(534)

S_r.t:$\langle$rel-pron$\rangle =$ Comp.t:$\langle$rel-pron$\rangle$  (534)0(534

(535)

S_r.b:$\langle$rel-pron$\rangle =$ S_r.b:$\langle$mode$\rangle$  (535)0(535

(536)

Comp.b:$\langle$rel-pron$\rangle =$ppart/ger/adj-clause (for $\epsilon$_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.

(536)0(536

(537)

the toy [$\epsilon$_i [$\epsilon$_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 $\langle$rel-pron$\rangle$ feature because of the following equation:

(537)0(537

(538)

S_m.b:$\langle$rel-pron$\rangle =$ S_f.t:$\langle$rel-pron$\rangle$ 

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

(538)0(538

(539)

On the root of the RC: NP_r.b:$\langle$rel-clause $\rangle = +$  (539)0(539

(540)

On the foot node of the Determiner tree: NP_f.t:$\langle$rel-clause $\rangle = -$