Sentential Subjects and Sentential Complements

In the XTAG grammar, arguments of a lexical item, including subjects, appear in the elementary tree anchored by that lexical item. A sentential argument appears as an S node in the appropriate position within an elementary tree anchored by the lexical item that selects it. This is the case for sentential complements of verbs, prepositions and nouns and for sentential subjects. The distribution of complementizers in English is intertwined with the distribution of embedded sentences. A successful analysis of complementizers in English must handle both the cooccurrence restrictions between complementizers and various types of clauses, and the distribution of the clauses themselves, in both subject and complement positions.