The nominative case is one of the grammatical cases common to many different languages. It is used primarily for nouns that are the subjects of sentences. Nouns in this case may have gender or number properties in some languages. Typically, the nominative case is also used as the default reference form for nouns, which are usually listed in this case in reference works.
Grammatical cases convey meaning about the structure of a sentence through the form taken by words in that sentence. Many languages, such as English, have evolved away from this style of communication and rely on word order to convey meaning instead. The nominative case is the most basic of all the cases, as it is used to indicate which noun is the grammatical subject of a sentence. Other cases may indicate which nouns are the direct or indirect objects of a sentence or indicate other nouns and pronouns with specific grammatical roles to play in a sentence.
Many languages feature gendered nouns, which leads to variation in the form of words listed in the nominative case. In such languages, the form of a word may have a telltale ending to indicate gender, as in Russian. Other languages, such as German, lack clear markers of grammatical gender in word structure but make a convention of using a gendered article with all nouns.
The nominative case typically includes different forms for singular and plural nouns. The specific means used to denote plural nouns vary widely from language to language and may include the addition of prefixes and suffixes or even larger changes to the structure of a word. To complicate matters further, some languages retain a third grammatical form, used for items that appear in twos. This form is archaic and vestigial in most languages, but still modifies the form of words in the nominative plural in many cases. Older nouns, and nouns that naturally occur in twos, such as "eyes" in Russian, are more apt to take this special form.
In English and some other languages, the nominative case has almost vanished. Vestigial traces of an older and more complicated grammar linger, however. Pronouns in English still take on different forms to reflect subject or object status, for instance. “I saw them” and “They saw me” are short examples of this. “John saw the doctor” and “The doctor saw John” display the more typical behavior of English nouns.
Reference works usually use the nominative case of nouns. Dictionaries for languages such as German, where gender is important but marked by an article, will generally include that article in addition to a noun in the nominative case. This practice is common even in languages, such as Russian, where it makes less sense at first glance. Russian words are very often built on word stems, to which each case, including the nominative case, then applies an ending. The presence of anomalous loan-words and special cases tips the balance in favor of the use of the nominative as a standard, as these words lack proper stems.