Ultrasound at Chikitsa Super Speciality Hospital, sector 51

In languages that employ articles, every common noun, with some exceptions, is expressed with a certain definiteness (e.g., definite or indefinite), just as many languages express every noun with a certain grammatical number (e.g., singular or plural). Every nounmust be accompanied by the article, if any, corresponding to its definiteness, and the lack of an article (considered a zero article) itself specifies a certain definiteness. This is in contrast to other adjectives and determiners, which are typically optional. This obligatory nature of articles makes them among the most common words in many languages—in English, for example, the most frequent word is the.