This article is about the grammatical change of word form in linguistics. For the change in pitch or loudness of the voice in linguistics, see Intonation (linguistics). For inflection in mathematics, see Inflection point. For music, see Diatonic and chromatic#chromatic inflection and Accidental (music).
In grammar, inflection or inflexion is the modification of a word to express different grammatical categories such as tense, grammatical mood, grammatical voice, aspect, person, number, genderand case. Conjugation is the inflection of verbs; declension is the inflection of nouns, adjectives andpronouns.
An inflection expresses one or more grammatical categories with an explicitly stated prefix, suffix, or infix, or another internal modification such as a vowel change. For example, the Latin ducam, meaning “I will lead”, includes an explicit suffix, -am, expressing person (first), number (singular), and tense (future). The use of this suffix is an inflection. In contrast, in the English clause “I will lead”, the word “lead” is not inflected for any of person, number, or tense; it is simply the bare formof a verb.
The inflected form of a word often contains both a free morpheme (a unit of meaning which can stand by itself as a word), and a bound morpheme (a unit of meaning which cannot stand alone as a word). For example, the English word “cars” is a noun that is inflected for number, specifically to express the plural; the content morpheme “car” is unbound because it could stand alone as a word, while the suffix “s” is bound because it cannot stand alone as a word. These two morphemes together form the inflected word “cars”.
Words that are never subjected to inflection are said to be invariant; for example, “must” is an invariant item: it never takes a suffix or changes form to signify a different grammatical category. Its category can only be determined by its context.
Requiring the inflections of more than one word in a sentence to be compatible according to the rules of the language is known as concord or agreement. For example, in “the choir sings”, “choir” is a singular noun, so “sing” is constrained in the present tense to use the third person singular suffix “s”.
Languages that have some degree of inflection are synthetic languages. These can be highly inflected, such as Latin, or weakly inflected, such as English. Languages that are so inflected that a sentence can consist of a single highly inflected word (such as many American Indian languages) are called polysynthetic languages. Languages in which each inflection conveys only a single grammatical category, such as Finnish, are known as agglutinative languages, while languages in which a single inflection can convey multiple grammatical roles (such as both nominative case and plural, as in Latin and German) are called fusional. Languages such as Mandarin Chinese that never use inflections are called analytic or isolating.
In English most nouns are inflected for number with the inflectional plural affix -s (as in “dog” → “dog-s“), and most English verbs are inflected for tense with the inflectional past tense affix -ed (as in “call” → “call-ed“). English also inflects verbs by affixation to mark the third person singular in the present tense (with -s), and the present participle (with -ing). English short adjectives are inflected to mark comparative and superlative forms (with -er and -est respectively). In addition, English also shows inflection by ablaut (sound change, mostly in verbs) and umlaut (a particular type of sound change, mostly in nouns), as well as long-short vowel alternation. For example:Examples in English
- Write, wrote, written (marking by ablaut variation, and also suffixing in the participle)
- Sing, sang, sung (ablaut)
- Foot, feet (marking by umlaut variation)
- Mouse, mice (umlaut)
- Child, children (ablaut, and also suffixing in the plural)
Declension and conjugation
Two traditional grammatical terms refer to inflections of specific word classes:
- Inflecting a noun, pronoun, adjective 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, or aspect.
Below is the declension of the English pronoun I, which is inflected for case and number.
The pronoun who is also inflected in formal English according to case. Its declension is defective, in the sense that it lacks a reflexive form.
|singular & plural|
|Tense||I||you||he, she, it||we||you||they|
The non-finite forms arrive (bare infinitive), arrived (past participle) and arriving (gerund/present participle), although not inflected for person or number, can also be regarded as part of the conjugation of the verb to arrive. Compound verb forms such as I have arrived, I had arrived, or I will arrive can be included also in the conjugation of this verb for didactical purposes, but are not overt conjugations ofarrive. The formula for deriving the covert form, in which the relevant inflections do not occur in the main verb, is
- pronoun + conjugated auxiliary verb + non-finite form of main verb.
A class of words with similar inflection rules is called an inflectional paradigm. Typically the similar rules amount to a unique set of affixes. Nominal inflectional paradigms are also called declensions, and verbal inflectional paradigms are also called conjugations. For example, in Old English nouns could be divided into two major declensions, the strong and the weak, inflected as is shown below:
|gender and number|
|case||Strong Noun Declension|
|engel ‘angel’||scip ‘ship’||sorg ‘sorrow’|
|case||Weak Noun Declension|
|nama ‘name’||ēage ‘eye’||tunge ‘tongue’|
The terms “strong declension” and “weak declension” are primarily relevant to well-known dependent-marking languages(such as the Indo-European languages, or Japanese). In dependent-marking languages, nouns in adpositional phrases can carry inflectional morphemes. (Adpositions include prepositions and postpositions.) In head-marking languages, the adpositions can carry the inflection in adpositional phrases. This means that these languages will have inflected adpositions. In Western Apache(San Carlos dialect), the postposition -ká’ ‘on’ is inflected for person and number with prefixes.
|1st||shi-ká||on me||noh-ká||on us two||da-noh-ká||‘on us’|
|2nd||ni-ká||on you||nohwi-ká||‘on you two’||da-nohwi-ká||‘on you all’|
|3rd||bi-ká||‘on him’||–||da-bi-ká||‘on them’|
Inflection vs. derivation
Inflection is the process of adding inflectional morphemes (smallest units of meaning) to a word, which indicate grammatical information (for example, case, number, person, gender or voice, mood, tense, or aspect). Derivation is the process of adding derivational morphemes, which create a new word from existing words, sometimes by simply changing grammatical category (for example, changing a noun to a verb).
Words generally are not listed in dictionaries (in which case they would be lexical items) on the basis of their inflectional morphemes. But they often are listed on the basis of their derivational morphemes. For instance, English dictionaries list readable and readability, words with derivational suffixes, along with their root read. However, no traditional English dictionary lists book as one entry and booksas a separate entry nor do they list jump and jumped as two different entries.
Languages that add inflectional morphemes to words are sometimes called inflectional languages, which is a synonym for inflected languages. Morphemes may be added in several different ways:
- Affixation, or simply adding morphemes onto the word without changing the root,
- Reduplication, doubling all or part of a word to change its meaning,
- Alternation, exchanging one sound for another in the root (usually vowel sounds, as in the ablaut process found in Germanic strong verbs and the umlaut often found in nouns, among others).
- Suprasegmental variations, such as of stress, pitch or tone, where no sounds are added or changed but the intonation and relative strength of each sound is altered regularly. For an example, see Initial-stress-derived noun.
Affixing includes prefixing (adding before the base), and suffixing (adding after the base), as well as the much less common infixing (inside) and circumfixing (a combination of prefix and suffix).