The term definite article refers to the word "the". In English we also have an indefinite article, "a" (or "an" before words beginning with vowels.)

In Greek there is no indefinite article. You will have to allow the context to tell you whether or not to supply an indefinite article in your English translation.

But Greek does have a definite article. It is declined for number, case, and gender as follows:

 

	Definite Article, "the"
		masculine			neuter
		sing.	plur.		sing.	plur.
	nom.	ὁ	οἱ		τό	τά
	gen.	τοῦ	τῶν		τοῦ	τῶν
	dat.	τῷ	τοῖς		τῷ	τοῖς
	acc.	τόν	τούς		τό	τά

Notice that there is no vocative.

Also notice the similarity between the definite article and the case endings.

Comparison of Masculine Definite Article and Case Endings

Notice that in the oblique cases (those cases other than the nominative) the definite article is simply the case ending with a τ prefixed and an accent mark added.

In the nominative case, there is no τ prefixed nor is there an accent mark, and in the nominative singular, the ς is dropped.

Comparison of Neuter Definite Article and Case Endings

τ is prefixed throughout, and the ν is dropped in the nom. sing. and acc. sing.

Agreement

The definite article must agree in number, case, and gender with the noun it modifies. Therefore, we should write,

τοὺς λόγους

not

τὸν λόγους (number does not agree)
οἱ λόγους (case does not agree)
τὰ λόγους (gender does not agree)

"Articular" vs. "Anarthrous"

We will have occasion to speak of articular constructions (those using the article) and anarthrous constructions (those not using the article). "Article" and "articular" come to us from the Latin word articulus (although Latin had no definite article). "-arthrous" comes to us from the Greek word, ἄρθρον meaning "joint" and used in grammar of connecting words such as relative pronouns (who, which) and demonstrative pronouns (this, that). It seems the definite article in Greek evolved from the demonstrative pronoun. (See Robertson, p. 755).

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