Grammatical personIn linguistics, grammatical person is the grammatical distinction between deictic references to participant(s) in an event; typically, the distinction is between the speaker (first person), the addressee (second person), and others (third person). A language's set of pronouns is typically defined by grammatical person. First person includes the speaker (English: I, we), second person is the person or people spoken to (English: thou or you ), and third person includes all that are not listed above (English: he, she, it, they).
DeclensionIn linguistics, declension (verb: to decline) is the changing of the form of a word, generally to express its syntactic function in the sentence, by way of some inflection. Declensions may apply to nouns, pronouns, adjectives, adverbs, and articles to indicate number (e.g. singular, dual, plural), case (e.g. nominative case, accusative case, genitive case, dative case), gender (e.g. masculine, neuter, feminine), and a number of other grammatical categories. Meanwhile, the inflectional change of verbs is called conjugation.
Grammatical caseA grammatical case is a category of nouns and noun modifiers (determiners, adjectives, participles, and numerals) which corresponds to one or more potential grammatical functions for a nominal group in a wording. In various languages, nominal groups consisting of a noun and its modifiers belong to one of a few such categories. For instance, in English, one says I see them and they see me: the nominative pronouns I/they represent the perceiver and the accusative pronouns me/them represent the phenomenon perceived.
Preposition and postpositionPrepositions and postpositions, together called adpositions (or broadly, in traditional grammar, simply prepositions), are a class of words used to express spatial or temporal relations (in, under, towards, before) or mark various semantic roles (of, for). A preposition or postposition typically combines with a noun phrase, this being called its complement, or sometimes object. A preposition comes before its complement; a postposition comes after its complement.