Extended projection principleThe extended projection principle (EPP) is a linguistic hypothesis about subjects. It was proposed by Noam Chomsky as an addendum to the projection principle. The basic idea of the EPP is that clauses must contain a noun phrase or determiner phrase in the subject position (i.e. in the specifier of a tense phrase or inflectional phrase or in the specifier of a verb phrase in languages in which subjects don't raise to TP/IP, e.g. Welsh). Most verbs require meaningful subjects—for example, "kick" in "Tom kicked the ball" takes the subject "Tom".
ComplementizerIn linguistics (especially generative grammar), a complementizer or complementiser (glossing abbreviation: ) is a (part of speech) that includes those words that can be used to turn a clause into the subject or object of a sentence. For example, the word that may be called a complementizer in English sentences like Mary believes that it is raining. The concept of complementizers is specific to certain modern grammatical theories. In traditional grammar, such words are normally considered conjunctions.
Finite verbTraditionally, a finite verb (from fīnītus, past participle of fīnīre - to put an end to, bound, limit) is the form "to which number and person appertain", in other words, those inflected for number and person. Verbs were originally said to be finite if their form limited the possible person and number of the subject. A more recent concept treats a finite verb as any verb that heads a simple declarative sentence. Under that newer articulation, finite verbs often constitute the locus of grammatical information regarding gender, person, number, tense, aspect, mood, and voice.
X-bar theoryIn linguistics, X-bar theory is a model of phrase-structure grammar and a theory of syntactic category formation that was first proposed by Noam Chomsky in 1970 reformulating the ideas of Zellig Harris (1951,) and further developed by Ray Jackendoff (1974, 1977a, 1977b), along the lines of the theory of generative grammar put forth in the 1950s by Chomsky. It attempts to capture the structure of with a single uniform structure called the X-bar schema, basing itself on the assumption that any phrase in natural language is an XP (X phrase) that is headed by a given X.