apophony is an alternation of vowel (quality) within a word that indicates grammatical information (often inflectional). It is also known as ablaut, (vowel) gradation In linguistics, apophony is an alternation of vowel (quality) within a word that indicates grammatical information (often inflectional). It is also known as ablaut, (vowel) gradation, (vowel) mutation, alternation, internal modification, stem modification, stem alternation, replacive morphology, stem mutation, or internal inflection. sing, sang, sung, song bind, bound blood, bleed, bled brood, breed, bred food, fodder, feed, fed lie, lay rise, rose, risen, rouse weave, weft, wove foot, feet goose, gosling, geese tooth, teeth The difference in these vowels marks variously a difference in tense or aspect (e.g. sing/sang/sung), transitivity (rise/raise), part of speech (sing/song), or grammatical number (goose/geese). That these sound alternations function grammatically can be seen as they are often equivalent to grammatical suffixes (an external modification). Compare the following: The vowel alternation between i and a indicates a difference between present and past tense in the pair sing/sang. Here the past tense is indicated by the vowel a just as the past tense is indicated on the verb jump with the past tense suffix -ed. Likewise, the plural suffix -s on the word books has the same grammatical function as the presence of the vowel ee in the word geese (where ee alternates with oo in the pair goose/geese). Consonants, too, can alternate in ways that are used grammatically. An example is the pattern in English of verb-noun pairs with related meanings but differing in voicing of a postvocalic consonant: Pros… Other analyses of these languages consider the patterns not to be sound alternations, but rather discontinuous roots with discontinuous affixes, known as transfixes (sometimes considered simulfixes or suprafixes). Some theoretical perspectives call up the notion of morphological templates or In linguistics, apophony is an alternation of vowel (quality) within a word that indicates grammatical information (often inflectional). It is also known as ablaut, (vowel) gradation, (vowel) mutation, alternation, internal modification, stem modification, stem alternation, replacive morphology, stem mutation, or internal inflection. sing, sang, sung, song bind, bound blood, bleed, bled brood, breed, bred food, fodder, feed, fed lie, lay rise, rose, risen, rouse weave, weft, wove foot, feet goose, gosling, geese tooth, teeth The difference in these vowels marks variously a difference in tense or aspect (e.g. sing/sang/sung), transitivity (rise/raise), part of speech (sing/song), or grammatical number (goose/geese). That these sound alternations function grammatically can be seen as they are often equivalent to grammatical suffixes (an external modification). Compare the following: The vowel alternation between i and a indicates a difference between present and past tense in the pair sing/sang. Here the past tense is indicated by the vowel a just as the past tense is indicated on the verb jump with the past tense suffix -ed. Likewise, the plural suffix -s on the word books has the same grammatical function as the presence of the vowel ee in the word geese (where ee alternates with oo in the pair goose/geese). Consonants, too, can alternate in ways that are used grammatically. An example is the pattern in English of verb-noun pairs with related meanings but differing in voicing of a postvocalic consonant: Prosodic alternations are sometimes analyzed not as a type of apophony but rather as prosodic affixes, which are known, variously, as suprafixes, superfixes, or simulfixes. Consonant alternation is commonly known as consonant mutation or consonant gradation. Bemba indicates causative verbs through alternation of the stem-final consonant. Here the alternation involves spirantization and palatalization: In Indo-European linguistics, ablaut is the vowel alternation that produces such related words as sing, sang, sung, and song. The difference in the vowels results from the alternation (in the Proto-Indo-European language) of the Here the singular/plural distinction is indicated through umlaut and additionally by a suffix -er in the plural form. English also displays similar forms with a -ren suffix in the plural and a -en suffix in the past participle forms along with the internal vowel alternation: The nonconcatenative morphology of the Afroasiatic languages is sometimes described in terms of apophony. The alternation patterns in many of these languages is quite extensive involving vowels and consonant gemination (i.e. doubled consonants). The alternations below are of Modern Standard Arabic, based on the root k–t–b 'write' (the symbol ⟨ː⟩ indicates gemination on the preceding consonant): Other analyses of these languages consider the patterns not to be sound alternations, but rather discontinuous roots with discontinuous affixes, known as transfixes (sometimes considered simulfixes or suprafixes). Some theoretical perspectives call up the notion of morphological templates or morpheme "skeletons". It would also be possible to analyze English in this way as well, where the alternation of goose/geese could be explained as a basic discontinuous root g-se that is filled out with an infix -oo- "(singular)" or -ee- "(plural)". Many would consider this type of analysis for English to be less desirable as this type of infixal morphology is not very prevalent throughout English and the morphemes -oo- and -ee- would be exceedingly rare. Ablaut reduplication, or ablaut-motivated compounding, is a type of word formation of "expressives" (such as onomatopoeia or ideophones), in which words are formed by reduplication of a base and alternation of the internal vowel. The pattern of vowel alternation in English follows a front to back vowel order, which among clipped vowels means a subset of /ɪ/ > /ɛ/ > /æ/ > /ʌ/ > /ɒ/ > /ʊ/, as in: