English forces a choice before many nouns: a, an, or the. An article is a type of determiner that marks a noun phrase as definite or indefinite and helps signal whether the referent is already known in the discourse.

Definite articles typically pick out a uniquely identifiable entity; indefinite articles introduce a non-unique or new entity. Some languages lack articles entirely and rely on word order, case, or context instead. Others have richer systems that also encode specificity or specificity-related distinctions.

Article use is a notorious difficulty for learners whose first language has no parallel category. Even advanced speakers may omit or overuse the in subtle contexts. Descriptive grammars devote considerable space to the pragmatic conditions that govern article choice.

• Determiner marking definiteness of a noun phrase
• Contrasts definite and indefinite reference
• Absent in some languages
• Challenging for second-language learners