There is considerable variation in the expression of definiteness across languages: some languages use a definite article (which can be a free form, a phrasal clitic, or an affix on the noun) to mark a definite noun phrase. Examples are:
Germanic, Romance, Celtic, Semitic, and auxiliary languages generally have a definite article, sometimes used as a postposition. Many other languages do not. Some examples are Chinese, Japanese, Finnish, and the Slavic languages except Bulgarian and Macedonian. When necessary, languages of this kind may indicate definiteness by other means such as Demonstratives.
It is common for definiteness to interact with the marking of case in certain syntactic contexts. In many languages direct objects (DOs) receive distinctive marking only if they are definite. For example in Turkish, the DO in the sentence adamları gördüm (meaning "I saw the men") is marked with the suffix -ı (indicating definiteness). The absence of the suffix means that the DO is indefinite ("I saw men").
In Serbo-Croatian, and to a lesser extent in Slovene, definiteness can be expressed morphologically on prenominal adjectives. The short form of the adjective is interpreted as indefinite (nov grad "a new city"), while the long form is definite and/or specific (novi grad "the new city, a certain new city").
In Japanese, a language which indicates noun functions with postpositions, the topic marker (wa) may include definiteness. For example, "uma wa" can mean "the horse", while "uma ga" can mean "a horse".