Inflection: How languages mark grammatical change

Inflection is the modification of words to express grammatical features — tense, number, case, gender, person and more. This article explains types, examples, typology and how inflection differs from derivation.

Author: Leandro Alegsa Creation date: November 13, 2022 Last updated: June 3, 2026

Inflection is the alteration of a word’s form to signal grammatical information such as tense, number, case, gender, mood or person. In other words, inflection adds or changes bits of a word to show how it functions inside a sentence rather than creating a new lexical item. In linguistics this is treated as an aspect of grammar, and the pieces attached to roots are generally called affixes.

How inflection works

Inflectional material most commonly appears as prefixes placed before a root or suffixes attached to the end. Some languages allow infixes (inserted inside a root), circumfixes (parts around a root) or complex templatic patterns where vowel changes mark grammar. Affixes are added to the stem of a word but do not normally change the basic lexical meaning in the same way derivational processes do.

Common grammatical categories expressed by inflection include:

Number (singular, plural),
Case (nominative, accusative, genitive, etc.),
Tense and aspect (past, present, progressive, perfect),
Mood and voice (subjunctive, imperative, passive),
Person and agreement (first, second, third person matching subject or object).

Examples and terminology

Inflection on verbs is often called conjugation, while inflection on nouns, pronouns and adjectives is known as declension. English shows limited inflectional marking: verbs have forms like write, writes, wrote, written; plural formation appears in dog → dogs; pronouns keep case contrasts (I, me, myself). English also preserves irregular patterns such as foot → feet and mouse → mice. Possession is shown by genitive marking (dog's, dogs') — see genitive case — and pronouns show case variation — see pronoun cases.

By contrast, classical languages such as Latin or Sanskrit have extensive inflectional paradigms covering many cases, numbers and verb forms. Some modern languages like English are relatively analytic and rely more on word order and auxiliary words, while languages such as Mandarin Chinese are largely isolating and make little use of inflectional affixes.

Typology, functions and distinctions

Linguists distinguish types of morphological synthesis: fusional languages fuse several grammatical meanings into a single affix; agglutinative languages string together a sequence of clear morphemes; isolating languages use few affixes at all. Inflection differs from derivation because it alters grammatical role without forming a new dictionary entry (happy → happier is inflectional degree; happy → happiness is derivational).

Inflection matters for language learning, historical linguistics and computational processing: it affects agreement rules, parsing strategies and dictionary organization. Irregular inflection, allomorphy (variant forms of the same morpheme), and zero-marking (no overt affix) are frequent complications. For further reading about related concepts, see general materials on grammar, affixes and the specific topics of conjugation and declension.

Inflections in German

In the grammatical definition, the types of inflection are distinguished depending on the part of speech.

Declination for nouns

Nouns are declined according to case and number, the genus is fixed.

Example:

the house, of the house, of the houses

adjectival declension

Adjectives are declined according to genus, case, numerus and comparison.

Declination	Example
by genus	a quick, a quick, a quick
by case	a quick, a quick, a quick, a quick
by numerus	one quick, two quick
after compensation	a faster, a faster

Three types of inflection can be distinguished:

weak declension with prefixed definite article word, example: in the big round, the old man
strong or pronominal declension in the case of a missing or inflectional article word, example: in large company, old man
mixed declension preceded by an indefinite article word, example: in a big round, an old man

verb conjugation

Verbs are conjugated by person, numerus, aspect, action type, tense, and mode.

There are three types of inflection for verbs in parallel:

weak, external inflection using affixes (prefixes, suffixes, infixes, circumfixes)

tense inflection by appending -{t}- to the stem in the past tense (for example, as in (I) play - played, (I) say - said)

strong, internal inflection with the change of the root vowel

for example by ablaut as in (I) singe - sang (tense inflection) and umlaut as in (I) fechte - (you) fichtst (inflection after the person) and (I) sang - sänge (inflection of the mode).

irregular (mixed) inflection with further change of the root vowel (ablaut and consonant change) as in (I) pull - pulled and sometimes additionally with the tense affix as in (I) bring - brought (vowel change, consonant change and preterite suffix -{t}-) or with suppletive forms as in (I) am - (you) are - (he) is, (you) are, (we, they) are, where different stems are included in the inflectional paradigm (suppletion).

Congruence and group reflection

The congruence of words or word groups in a sentence can be indicated by congruence. In German, this is mainly the case, numerus and genus congruence within a clause, the numerus congruence between subject and predicate as well as the numerus and genus congruence between reference noun and relative pronoun.

Example: We see the little boy. The sentence has a numerical congruence between subject and predicate, and a case, numerical and gender congruence in the object.

Agglutinative languages such as the Turkic languages express the affiliation of (adjective-)attributes (also number words and demonstrative pronouns), not by congruence, but by group inflection. In this case, the subordinate attributes are prefixed to the noun in their uninflected base form, resulting in a group. This is then subjected to inflection as a whole, i.e. only the noun provided with attributes carries numerus and case markers (morphemes for marking the case).

Author

Creation date: November 13, 2022

Last updated: June 3, 2026