prefer to define nouns (and other lexical categories) in terms of their formal properties. These include morphological information, such as what prefixes or suffixes they take, and also their syntax – how they combine with other words and expressions of particular types. Such definitions may nonetheless still be language-specific since syntax as well as morphology varies between languages. For example, in English, it might be noted that nouns are words that can co-occur with definite articles (as stated at the start of this article), but this would not apply in Russian, which has no definite articles. A functional approach defines a noun as a word that can be the head of a nominal phrase, i.e. a phrase with referential function, without needing to go through morphological transformation. Classification Nouns can have a number of different properties and are often sub-categorized based on various of these criteria, depending on their occurrence in a language. Gender In some languages, genders are assigned to nouns, such as masculine, feminine and neuter. The gender of a noun (as well as its number and case, where applicable) will often entail agreement in words that modify or are related to it. For example, in French, the singular form of the definite article is le for masculine nouns and la for feminine; adjectives and certain verb forms also change (with the addition of for feminine). Grammatical gender often correlates with the form of the noun and the inflection pattern it follows; for example, in both Italian and Russian most nouns ending are feminine. Gender can also correlate with the sex of the noun's referent, particularly in the case of nouns denoting people (and sometimes animals). Nouns arguably do not have gender in Modern English, although many of them denote people or animals of a specific sex (or social gender), and pronouns that refer to nouns must take the appropriate gender for that noun. (The girl lost her spectacles.) Proper and common nouns A proper noun or proper name is a noun representing unique entities (such as India, Pegasus, Jupiter, Confucius, or Pequod), as distinguished from common nouns, which describe a class of entities (such as country, animal, planet, person or ship). Countable nouns and mass nouns Count nouns or countable nouns are common nouns that can take a plural, can combine with numerals or counting quantifiers (e.g., one, two, several, every, most), and can take an indefinite