Esperanto grammar

Esperanto is a constructed auxiliary language. A highly regular grammar makes Esperanto easier to learn than other languages of the world. Native speakers of Chinese and English can both learn it to fluency within four months, without having known another foreign language beforehand.

Each part of speech has a unique suffix: nouns end with ‑o; adjectives with ‑a; present‑tense indicative verbs with ‑as, and so on.

It is possible to communicate effectively with a vocabulary of 400 to 500 "meaning words", though more exist in the language. The original vocabulary of Esperanto had around 900 meaning words, but was quickly expanded.

Reference grammars include the Plena Analiza Gramatiko () (English: Complete Analytical Grammar) by Kálmán Kalocsay and Gaston Waringhien, and the Plena Manlibro de Esperanta Gramatiko (English: Complete Handbook of Esperanto Grammar) by Bertilo Wennergren.

Esperanto has an agglutinative morphology, no grammatical gender, and simple verbal and nominal inflections. Verbal suffixes indicate four moods, of which the indicative has three tenses, and are derived for several aspects, but do not agree with the grammatical person or number of their subjects. Nouns and adjectives have two cases, nominative/oblique and accusative/allative, and two numbers, singular and plural; the adjectival form of personal pronouns behaves like a genitive case. Adjectives generally agree with nouns in case and number. In addition to indicating direct objects, the accusative/allative case is used with nouns, adjectives and adverbs to show the destination of a motion, or to replace certain prepositions; the nominative/oblique is used in all other situations. The case system allows for a flexible word order that reflects information flow and other pragmatic concerns, as in Russian, Greek, and Latin.

...
Wikipedia