Nominative case

In grammar, the nominative case (abbreviated NOM), subjective case, straight case, or upright case is one of the grammatical cases of a noun or other part of speech, which generally marks the subject of a verb, or (in Latin and formal variants of English) a predicative nominal or adjective, as opposed to its object, or other verb arguments. Generally, the noun "that is doing something" is in the nominative, and the nominative is often the form listed in dictionaries.