Declension - conjugation

In almost all languages there can be (usually small) changes to the form of some words. These changes reflect either the different parts which the word can play in a sentence (e.g., in the case of a noun whether it is the subject or object of the verb) or (slight) differences in the meaning of the word (e.g., in the case of a noun whether it is singular or plural, or in the case of a verb whether its subject is in the first person, second person, or third person and whether it is in the past, present or future tense). Typically, though not always, these changes involve a change in the ending of the word while the rest of the word - the stem - remains unchanged. When we change the form of a word in this way we are said to inflect it (from the Latin inflectere, which means: to bend or alter). The associated noun is inflection.

Incidentally, English is a relatively uninflected language: it does not involve the inflection of words to any great extent, unlike many other ancient and modern languages, such as Latin and Greek, German, Russian, and Arabic.

• In grammar we use different sets of words to talk about the inflection of nouns, pronouns, and adjectives, on the one hand, and the inflection of verbs, on the other.

• When we list systematically the different forms of a noun, pronoun, or adjective we are said to decline it. (from the Latin verb declinare, which means to bend away or inflect grammatically). The related noun declension means either the act of declining such a word or a systematic list of the different forms which the word can have. Here, as an example, is the declension (i.e., a systematic list of the different forms) of the Latin word hortus (garden) in the singular:

Declension of hortus

Nominative case	hortus	'garden' as subject of a verb
Vocative case	horte	used to address a garden: O garden
Accusative case	hortum	'garden' as object of a verb
Genitive case	horti	used to indicate possession: of a garden
Dative case	horto	'garden' as indirect object of the verb: to a garden
Ablative case	horto	by, with, or from a garden

For more on the different cases see Case in grammar.

In Latin and in many other languages not all nouns have the same set of endings for the different cases, i.e., there are different declensions of nouns. In Latin there are in fact five declensions.

• When we list systematically the different forms of a verb we are said to conjugate it. (from the Latin verb conjugare, which means: to join together) The related noun conjugation means either the act of conjugating a verb or a systematic list of the different forms which the verb can have. Here, as an example, is the conjugation (i.e., a systematic list of the different forms) of the Latin verb laborare (to work) in the present tense:

Conjugation of present tense of laborare

First person singular	laboro	I work
Second person singular	laboras	you (singular) work
Third person singular	laborat	he or she works
First person plural	laboramus	we work
Second person plural	laboratis	you (plural) work
Third person plural	laborant	they work

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In Latin and in many other languages not all verbs have the same set of endings for the different possibilities, i.e., there are different conjugations of verbs. In Latin there are in fact four conjugations.