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, gender and case. Conjugation is the inflection of verbs; declension is the inflection of nouns, adjectives and pronouns.
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 form of 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:
Two traditional grammatical terms refer to inflections of specific word classes:
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 of arrive. 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'|
Traditional grammars have specific terms for inflections of nouns and verbs, but not for those of adpositions.
See main article: Derivation (linguistics).
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
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 books as 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:
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).
All Indo-European languages, such as Albanian, English, German, Russian, Persian, Kurdish (kurdî), Italian, Spanish, French, Sanskrit, Marathi, Bengali and Hindi are inflected to a greater or lesser extent. In general, older Indo-European languages such as Latin, Greek, Old English, Old Norse, and Sanskrit are extensively inflected. Deflexion has caused modern versions of some languages that were previously highly inflected to be much less so; an excellent example is Modern English, as compared to Old English. Most Slavic languages are an exception to the general Indo-European deflexion trend, continuing to be highly inflected (in some cases acquiring additional inflectional complexity and grammatical genders, as in Czech).
Old English was a moderately inflected language, using an extensive case system similar to that of modern Icelandic or German. Middle and Modern English lost progressively more of the Old English inflectional system. Modern English is considered a weakly inflected language, since its nouns have only vestiges of inflection (plurals, the pronouns), and its regular verbs have only four forms: an inflected form for the past indicative and subjunctive (looked), an inflected form for the third-person-singular present indicative (looks), an inflected form for the present participle (looking), and an uninflected form for everything else (look). While the English possessive indicator 's (as in "Jane's book") is a remnant of the Old English genitive case suffix, it is now considered not a suffix but a clitic.
Old Norse was inflected, but modern Swedish, Norwegian and Danish have, like English, lost almost all overt inflection. Icelandic preserves almost all of the inflections of Old Norse and has added its own. Modern German remains moderately inflected, retaining four noun cases, although the genitive started falling into disuse in all but formal writing in Early New High German. The case system of Dutch, simpler than that of German, is also simplified in common usage. Afrikaans, recognized as a distinct language in its own right rather than a Dutch dialect only in the early 20th century, has lost almost all inflection.
The Romance languages, such as Spanish, Italian, French, Portuguese and Romanian, have more overt inflection than English, especially in verb conjugation. Adjectives, nouns and articles are considerably less inflected than verbs, but they still have different forms according to number and grammatical gender.
Latin, the mother tongue of the Romance languages, was highly inflected; nouns and adjectives had different forms according to seven grammatical cases (including five major ones) with five major patterns of declension, and three genders instead of the two found in most Romance tongues. There were four patterns of conjugation in six tenses, two moods and two voices, all overtly expressed by affixes (passive voice forms were periphrastic in three tenses).
The Baltic languages are highly inflected. Nouns and adjectives are declined in up to seven overt cases. Additional cases are defined in various covert ways. For example, an inessive case, an illative case, an adessive case and allative case are borrowed from Finnic. Latvian has only one overt locative case but it syncretizes the above four cases to the locative marking them by differences in the use of prepositions. Lithuanian breaks them out of the genitive case, accusative case and locative case by using different postpositions.
Modern Baltic languages have also retained the old dual number. However, it is nowadays considered obsolete. For instance, in standard Lithuanian it is normal to say "dvi varnos (plural) – two crows" instead of "dvi varni (dual)". Adjectives, pronouns, and numerals are declined for number, gender, and case to agree with the noun they modify or for which they substitute. Baltic verbs are inflected for tense, mood, aspect, and voice. They agree with the subject in person and number (not in all forms in modern Latvian).
All Slavic languages make use of a high degree of inflection, typically having six or seven cases and three genders for nouns and adjectives. However, the overt case system has disappeared almost completely in modern Bulgarian and Macedonian. Most verb tenses and moods are also formed by inflection (however, some are periphrastic, typically future and conditional). Inflection is also present in adjective comparation and word derivation.
Declensional endings depend on case (nominative, genitive, dative, accusative, locative, instrumental, vocative), number (singular, dual or plural), gender (masculine, feminine, neuter) and animacy (animate vs inanimate). Unusual in other language families, declension in most Slavic languages also depends on whether the word is a noun or an adjective. Slovene and Sorbian languages use a rare third number, (in addition to singular and plural numbers) known as dual (in case of some words dual survived also in Polish and other Slavic languages). In addition, in some Slavic languages, such as Polish, word stems are frequently modified by the addition or absence of endings, resulting in consonant and vowel alternation.
Modern Standard Arabic (also called Literary Arabic) is a highly inflected language. It uses a complex system of pronouns and their respective prefixes and suffixes for verb, noun, adjective and possessive conjugation. In addition, the system known as places vowel suffixes on each verb, noun, adjective, and adverb, according to its function within a sentence and its relation to surrounding words.
The following table is an example of present-tense case applications in Arabic:
|Pronoun||Possessive Suffix||Verb Affixes||Pronoun||Possess. Suffix||Verb Affixes||Pronoun||Possess. Suffix||Verb Affixes|
|I||Arabic: أَنَا <small>/anā/</small>||Arabic: ـِـي <small>/—ī/</small>||Arabic: أَ <small>/a—/</small>||Arabic: نَحْنُ <small>/naḥnu/</small>||Arabic: ــنَا <small>/—nā/</small>||Arabic: نــ <small>/n—/</small>||–||–||–|
|you (masc.)||Arabic: أَنْتَ <small>/anta/</small>||Arabic: ــكَ <small>/—ka/</small>||Arabic: تــــــ <small>/t—/</small>||Arabic: أَنْتُمْ <small>/antum/</small>||Arabic: ــكُمْ <small>/—kum/</small>||Arabic: تــــــــــــُونَ <small>/t—ūn/</small>||Arabic: أَنْتُمَا <small>/antumā/</small>||Arabic: ــكُمَا <small>/—kumā/</small>||Arabic: تــــــــــــَانِ <small>/t—āni/</small>|
|you (fem.)||Arabic: أَنْتِ <small>/anti/</small>||Arabic: ــكِ <small>/—ki/</small>||Arabic: تــــــــــــِينَ <small>/t—īna/</small>||Arabic: أَنْتُنَّ <small>/antunna/</small>||Arabic: ــكُنَّ <small>/—kunna/</small>||Arabic: تـــــــــــــْنَ <small>/t—na/</small>|
|he||Arabic: هُوَ <small>/huwa/</small>||Arabic: ــهُ <small>/—hu/</small>||Arabic: يــ <small>/y—/</small>||Arabic: هُمْ <small>/hum/</small>||Arabic: ــهُمْ <small>/—hum/</small>||Arabic: يــــــــــــُونَ <small>/y—ūna/</small>||Arabic: هُمَا <small>/humā/</small>||Arabic: ــهُمَا <small>/—humā/</small>||Arabic: يــــــــــــَانِ <small>/y—āni/</small>|
|she||Arabic: هِيَ <small>/hiya/</small>||Arabic: ــهَا <small>/—hā/</small>||Arabic: تــ <small>/t—/</small>||Arabic: هُنَّ <small>/hunna/</small>||Arabic: ــهُنَّ <small>/—hunna/</small>||Arabic: تـــــــــــــْنَ <small>/t—na/</small>|
Arabic regional dialects (e.g. Moroccan Arabic, Egyptian Arabic, Gulf Arabic), used for everyday communication, tend to have less inflection than the more formal Literary Arabic. For example, in Jordanian Arabic, the second- and third-person feminine plurals (Arabic: أنتنّ /antunna/ and Arabic: هنّ /hunna/) and their respective unique conjugations are lost and replaced by the masculine (Arabic: أنتم /antum/ and Arabic: هم /hum/), whereas in Lebanese and Syrian Arabic, Arabic: هم /hum/ is replaced by Arabic: هنّ /hunna/.
The Uralic languages are agglutinative, following from the agglutination in Proto-Uralic. The largest languages are Hungarian, Finnish, and Estonian—all European Union official languages. Uralic inflection is, or is developed from, affixing. Grammatical markers directly added to the word perform the same function as prepositions in English. Almost all words are inflected according to their roles in the sentence: verbs, nouns, pronouns, numerals, adjectives, and some particles.
Hungarian and Finnish, in particular, often simply concatenate suffixes. For example, Finnish talossanikinko "in my house, too?" consists of talo-ssa-ni-kin-ko. However, in the Finnic languages (Finnish, Estonian, Sami), there are processes which affect the root, particularly consonant gradation. The original suffixes may disappear (and appear only by liaison), leaving behind the modification of the root. This process is extensively developed in Estonian and Sami, and makes them also inflected, not only agglutinating languages. The Estonian accusative case, for example, is expressed by a modified root: maja →majja (historical form *majam).
The three language families often united as Altaic languages—Turkic, Mongolic, and Manchu-Tungus—are agglutinative. The largest languages are Turkish, Azerbaijani and Uzbek—all Turkic languages. Altaic inflection is, or is developed from, affixing. Grammatical markers directly added to the word perform the same function as prepositions in English. Almost all words are inflected according to their roles in the sentence: verbs, nouns, pronouns, numerals, adjectives, and some particles.
Basque, a language isolate, is an extremely inflected language, heavily inflecting both nouns and verbs. A Basque noun is inflected in 17 different ways for case, multiplied by 4 ways for its definiteness and number. These first 68 forms are further modified based on other parts of the sentence, which in turn are inflected for the noun again. It is estimated that at two levels of recursion, a Basque noun may have 458,683 inflected forms. Verb forms are similarly complex, agreeing with the subject, the direct object and several other arguments.
Some of the major Eastern Asian languages (such as the various Chinese languages, Vietnamese, and Thai) are not overtly inflected, or show very little overt inflection, so they are considered analytic languages (also known as isolating languages).
The Chinese family of languages, in general, does not possess overt inflectional morphology. Chinese words generally comprise one or two monosyllabic written characters, each of which can also stand alone as an unbound morpheme. Since morphemes are monosyllabic in the Chinese languages, Chinese is quite resistant to inflectional changes; instead, Chinese uses lexical means for achieving covert inflectional transparency.
While European languages more often use overt inflection to mark a word's function in a sentence, the Chinese languages tend to use word order as a grammatical marking system. Whereas in English the first-person singular nominative "I" changes to "me" when used in the accusative – that is, as the object of a verb – Chinese simply uses word order to mark such a distinction. An example from Mandarin: 我给了他一本书 (wǒ gěile tā yī běn shū) 'I gave him a book'. Here 我 (wǒ) means 'I' and 他 (tā) means 'him'. However, 'He gave me a book' would be: 他给了我一本书 (tā gěile wǒ yī běn shū). 我 (Wǒ) and 他 (Tā) simply change places in the sentence to indicate that their case has switched: there is no overt inflection in the form of the words. In classical Chinese, pronouns were overtly inflected as to case. However, these overt case forms are no longer used; most of the alternative pronouns are considered archaic in modern Mandarin Chinese. Classically, 我 (wǒ) was used solely as the first person accusative. 吾 (Wú) was generally used as the first person nominative.
Japanese shows a high degree of overt inflection of verbs, less so of adjectives, and very little of nouns, but it is mostly strictly agglutinative and extremely regular. Some fusion of morphemes does take place (e.g. causative-passive -sare- as in ikasareru "is made to go", and non-past progressive -ter- as in tabeteru "is eating"), but this is rare. Formally, every noun phrase must be marked for case, but this is done by invariable particles (clitic postpositions). (Many grammarians consider Japanese particles to be separate words, and therefore not an inflection, while others consider agglutination a type of overt inflection, and therefore consider Japanese nouns as overtly inflected.)
Auxiliary languages, such as Esperanto, Ido, and Interlingua have comparatively simple inflectional systems.
In Esperanto, an agglutinative language, nouns and adjectives are inflected for case (nominative, accusative) and number (singular, plural), according to a simple paradigm without irregularities. Verbs are not inflected for person or number, but they are inflected for tense (past, present, future) and mood (indicative, infinitive, conditional, jussive). They also form active and passive participles, which may be past, present or future. All verbs are regular.
Ido has a different form for each verbal tense (past, present, future, volitive and imperative) plus an infinitive, and both a present and past participle. There are though no verbal inflections for person or number, and all verbs are regular.
Nouns are marked for number (singular and plural), and the accusative case may be shown in certain situations, typically when the direct object of a sentence precedes its verb. On the other hand, adjectives are unmarked for gender, number or case (unless they stand on their own, without a noun, in which case they take on the same desinences as the missing noun would have taken). The definite article "la" ("the") remains unaltered regardless of gender or case, and also of number, except when there is no other word to show plurality. Pronouns are identical in all cases, though exceptionally the accusative case may be marked, as for nouns.
Interlingua, in contrast with the Romance languages, has no irregular verb conjugations, and its verb forms are the same for all persons and numbers. It does, however, have compound verb tenses similar to those in the Romance, Germanic, and Slavic languages: ille ha vivite, "he has lived"; illa habeva vivite, "she had lived". Nouns are inflected by number, taking a plural -s, but rarely by gender: only when referring to a male or female being. Interlingua has no noun-adjective agreement by gender, number, or case. As a result, adjectives ordinarily have no inflections. They may take the plural form if they are being used in place of a noun: le povres, "the poor".