The Article.
The Definite Article the is in Esperanto represented by la. Like the article in English, la does not vary with the number or gender of the noun before which it is placed; e.g., la briko, the brick; la brikoj, the bricks; la patro, the father; la patrinoj, the mothers.
The Indefinite Article a is not expressed in Esperanto. Thus, "filo" is son or a son.
The Noun.
In Esperanto every noun in the singular ends in o. Thus: viro, a man; la libro, the book. The plural is formed from the singular by adding the termination -j. Thus: viroj, men; la libroj, the books.
In order to allow each nation to construct its sentences in the order to which it is accustomed, every noun in Esperanto has two forms or "cases," (1) the Nominative, or unchanged form, and (2) the Accusative, which is formed from the nominative by adding the termination -n. This is merely to distinguish between subject and object. The accusative form is also used to indicate motion towards, etc.
The Adjective.
All adjectives end in the nominative singular in a. They may be placed either before or after the noun. As in the case of the noun, the plural is formed by adding the termination -j, and the accusative is formed by adding -n to the nominative. The adjective agrees in number and case with the noun which it qualifies. Ex.:—
- Blua libro (or libro blua), a blue book; bluaj libroj, blue books.
- La viro legas bluan libron. The man reads a blue book.
- La viroj legas bluajn librojn. The men are reading blue books.
Thanks to the accusative case, one might say without loss of clearness: Bluan libron legas la viro, or la viro bluan libron legas, or bluan libron la viro legas, etc.