I. Regular and irregular inflection

Declension and conjugation

Main articles: Declension and Grammatical conjugation

Two traditional grammatical terms refer to inflections of specific word classes:

• 
  Inflecting a noun, pronoun, adjective, article or determiner is known as declining it. The affixes may express number, case, or gender.
  
• 
  Inflecting a verb is called conjugating it. The affixes may express tense, mood, voice, aspect, person, or number.
  

An organized list of the inflected forms of a given lexeme or root word is called its declension if it is a noun, or its conjugation if it is a verb.

Below is the declension of the English pronoun I, which is inflected for case and number.