Nouns and their relatives: introduction

• Nouns, adjectives, and pronouns have a system of inflection known as declining; the different sets of possible endings are known as declensions. For verbs, the equivalent term is conjugation; we speak of declining nouns but conjugating verbs.
  

• There are three grammatical elements of the way nouns and their relatives change their endings: case, number, and gender.
  • Number is the easiest to grasp: just as in English, a noun can be singular or plural: thing or things, woman or women. You can also have singular or plural pronouns: I or we, he or they.

  • Case is the most important element of a noun ending. It's what tells you how a word relates to the other words around it, and especially to the verb that is the engine room of any Latin sentence. Five of the six Latin cases do actually also exist in English - we just don't notice them because they mostly have the same form.
    

  • Gender is mostly obsolete in English, but we still have genders of third-person singular pronouns: he, she, it; him, her, it. Why we go unisex in the other persons, or in the plurals, is one of the many bonkers things about English: why not have different words for "you" or "they" to show whether you're speaking to or about blokes or women or tubs of lard? Some English nouns, especially in -er, have masculine and feminine forms: adulterer, adulteress. But in Latin all nouns have a gender - and all adjectives and pronouns can change their gender according to the gender of the noun they're referring to.