Clause Type

There are several features that mark clause type.^28.2 They are:
$\langle$mode$\rangle$
$\langle$passive$\rangle$: possible values are +/- $\langle$mode$\rangle$: possible values are base, ger, ind, inf, imp, nom, ppart, prep, sbjnct
The $\langle$mode$\rangle$ feature of a verb in its root form is base. The $\langle$mode$\rangle$ feature of a verb in its past participial form is ppart, the $\langle$mode$\rangle$ feature of a verb in its progressive/gerundive form is ger, the $\langle$mode$\rangle$ feature of a tensed verb is ind, and the $\langle$mode$\rangle$ feature of a verb in the imperative is imp. nom is the $\langle$mode$\rangle$ value of AP/NP predicative trees headed by a null copula. prep is the $\langle$mode$\rangle$ value of PP predicative trees headed by a null copula. Only the copula auxiliary tree, some sentential complement verbs (such as consider and raising verb auxiliary trees have nom/prep as the $\langle$mode$\rangle$ feature specification of their foot node. This allow them, and only them, to adjoin onto AP/NP/PP predicative trees with null copulas.