Mission of Words

Words - the minimal pieces of language - are traditionally considered to perform nine grammatical functions:
1. Nouns or names: they fulfill the most important mission within the language, by designating all beings —animate and inanimate, of real or imaginary existence— that make up the Universe. They are "the masters" of the syntax, since they determine all the accidents that variable words suffer within sentences.
2. Pronouns: replace nouns or sets of words.
3. Adjectives: qualify or determine nouns.
4. Articles: determine nouns and substantiated functions.
5. Verbs: indicate the existence, actions or states (including feelings, sensations, etc.) of nouns, with a certain location within time.
6. Adverbs: they serve verbs, adjectives or other adverbs, to indicate the different circumstances - mode, time, place, etc. - that accompany the actions, qualifications or stated determinations.
7. Prepositions: join grammatical elements, indicating dependence.
8. Conjunctions: join independent grammatical elements.

9. Interjections: they express, independently, different moods or intentions, such as called, beg, encouragement, admiration, annoyance, pain, joy, surprise, fright, contempt and others Similar.
(Modern grammatical trends reduce these functions to seven: they include articles in adjectives, and pronouns in nouns or nouns.)