Opening

In the opening type of lenition, the articulation becomes more open with each step. Opening lenition involves several sound changes: shortening of double consonants, affrication of stops, spirantization or assibilation of stops or affricates, debuccalization, and finally elision.

• [tt]Category:Pages with plain IPA or [tː]Category:Pages with plain IPA > [t]Category:Pages with plain IPA (shortening, example in Greek)
• [t]Category:Pages with plain IPA > [ts]Category:Pages with plain IPA (affrication, for example Latin: terraCategory:Articles containing Latin-language text to Aromanian: tsarãCategory:Articles containing Aromanian-language text)
• [t]Category:Pages with plain IPA or [ts]Category:Pages with plain IPA > [s]Category:Pages with plain IPA (spirantization, example in Gilbertese language)
• [t̚]Category:Pages with plain IPA > [ʔ]Category:Pages with plain IPA; [s]Category:Pages with plain IPA > [h]Category:Pages with plain IPA (debuccalization, example in English or Spanish)
• [t]Category:Pages with plain IPA, [ts]Category:Pages with plain IPA, [s]Category:Pages with plain IPA, [ʔ]Category:Pages with plain IPA, [h]Category:Pages with plain IPA > ∅ (elision, for example Old French: festeCategory:Articles containing Old French (842-ca. 1400)-language text to French: fêteCategory:Articles containing French-language text (cf. Spanish: fiestaCategory:Articles containing Spanish-language text))

Sonorization

The sonorization type involves voicing. Sonorizing lenition involves several sound changes: voicing, approximation, and vocalization.Category:Wikipedia articles needing clarification from February 2015^{[clarification needed]}

• [t]Category:Pages with plain IPA > [d]Category:Pages with plain IPA (voicing, example in Korean)
• [d]Category:Pages with plain IPA > [ð]Category:Pages with plain IPA (approximation, example in Spanish)
• [d]Category:Pages with plain IPA > [i]Category:Pages with plain IPA (vocalization)

Sonorizing lenition occurs especially often intervocalically (between vowels). In this position, lenition can be seen as a type of assimilation of the consonant to the surrounding vowels, in which features of the consonant that are not present in the surrounding vowels (e.g. obstruction, voicelessness) are gradually eliminated.

Some of the sounds generated by lenition are often subsequently "normalized" into related but cross-linguistically more common sounds. An example would be the changes [b]Category:Pages with plain IPA → [β]Category:Pages with plain IPA → [v]Category:Pages with plain IPA and [d]Category:Pages with plain IPA → [ð]Category:Pages with plain IPA → [z]Category:Pages with plain IPA. Such normalizations correspond to diagonal movements down and to the right in the above table. In other cases, sounds are lenited and normalized at the same time; examples would be direct changes [b]Category:Pages with plain IPA → [v]Category:Pages with plain IPA or [d]Category:Pages with plain IPA → [z]Category:Pages with plain IPA.

Mixed

Sometimes a particular example of lenition mixes the opening and sonorization pathways. For example, [kʰ]Category:Pages with plain IPA may spirantize or open to [x]Category:Pages with plain IPA, then voice or sonorize to [ɣ]Category:Pages with plain IPA.

Lenition can be seen in Canadian and American English, where /t/Category:Pages with plain IPA and /d/Category:Pages with plain IPA soften to a tap [ɾ]Category:Pages with plain IPA (flapping) when not in initial position and followed by an unstressed vowel. For example, both rate and raid plus the suffix -er are pronounced [ˈɹeɪ̯ɾɚ]Category:Pages with plain IPA. The Italian of Central and Southern Italy has a number of lenitions, the most widespread of which is the deaffrication of /t͡ʃ/Category:Pages with plain IPA to [ʃ]Category:Pages with plain IPA between vowels: post-pausal cenaCategory:Articles containing Italian-language text [ˈt͡ʃeːna]Category:Pages with plain IPA 'dinner' but post-vocalic la cenaCategory:Articles containing Italian-language text [laˈʃeːna]Category:Pages with plain IPA 'the dinner'; the name LucianoCategory:Articles containing Italian-language text, although structurally /luˈt͡ʃano/Category:Pages with plain IPA, is normally pronounced [luˈʃaːno]Category:Pages with plain IPA. In Tuscany, /d͡ʒ/Category:Pages with plain IPA likewise is realized [ʒ]Category:Pages with plain IPA between vowels, and in typical speech of Central Tuscany, the voiceless stops /p t k/Category:Pages with plain IPA in the same position are pronounced respectively [ɸ θ x/h]Category:Pages with plain IPA, as in /la kasa/Category:Pages with plain IPA → [laˈhaːsa]Category:Pages with plain IPA 'the house', /buko/Category:Pages with plain IPA → [ˈbuːho]Category:Pages with plain IPA 'hole'.

Diachronic

Diachronic lenition is found, for example, in the change from Latin into Spanish, in which the intervocalic voiceless stops [p t k]Category:Pages with plain IPA first changed into their voiced counterparts [b d ɡ]Category:Pages with plain IPA, and later into the approximants or fricatives [β̞ ð̞ ɣ̞]Category:Pages with plain IPA: vitaCategory:Articles containing Latin-language text > vidaCategory:Articles containing Spanish-language text, lupaCategory:Articles containing Latin-language text > lobaCategory:Articles containing Spanish-language text, caecaCategory:Articles containing Latin-language text > ciegaCategory:Articles containing Spanish-language text, apothecaCategory:Articles containing Latin-language text > bodegaCategory:Articles containing Spanish-language text. One stage in these changes goes beyond phonetic to have become a phonological restructuring, e.g. /lupa/Category:Pages with plain IPA > /loba/Category:Pages with plain IPA (compare /lupa/Category:Pages with plain IPA in Italian, with no change in the phonological status of /p/Category:Pages with plain IPA). The subsequent further weakening of the series to phonetic [β̞ ð̞ ɣ̞]Category:Pages with plain IPA, as in [loβ̞a]Category:Pages with plain IPA is diachronic in the sense that the developments took place over time and displaced [b, d, g]Category:Pages with plain IPA as the normal pronunciations between vowels. It is also synchronic in an analysis of [β̞ ð̞ ɣ̞]Category:Pages with plain IPA as allophonic realizations of /b, d, g/Category:Pages with plain IPA: illustrating with /b/Category:Pages with plain IPA, /bino/Category:Pages with plain IPA 'wine' is pronounced [bino]Category:Pages with plain IPA after pause, but with [β̞]Category:Pages with plain IPA intervocalically, as in [de β̞ino]Category:Pages with plain IPA 'of wine'; likewise, /loba/Category:Pages with plain IPA → [loβ̞a]Category:Pages with plain IPA.

A similar development occurred in the Celtic languages, where non-geminate intervocalic consonants were converted into their corresponding weaker counterparts through lenition (usually stops into fricatives but also laterals and trills into weaker laterals and taps), and voiceless stops became voiced. For example, Indo-European intervocalic *-t-Category:Articles containing Proto-Indo-European-language text in *teu̯teh₂Category:Articles containing Proto-Indo-European-language text "people" resulted in Proto-Celtic *toutā, Primitive Irish *tōθāCategory:Articles containing Primitive Irish-language text, Old Irish túath /t̪ʰuaθ/Category:Pages with plain IPA and ultimately debuccalisation in most Irish and some Scottish dialects to /t̪ʰuəh/Category:Pages with plain IPA, shift in Central Southern Irish to /t̪ʰuəx/Category:Pages with plain IPA, and complete deletion in some Modern Irish and most Modern Scots Gaelic dialects, thus /t̪ʰuə/Category:Pages with plain IPA.^[1]

An example of historical lenition in the Germanic languages is evidenced by Latin-English cognates such as paterCategory:Articles containing Latin-language text, tenuisCategory:Articles containing Latin-language text, cornuCategory:Articles containing Latin-language text vs. father, thin, horn. The Latin words preserved the original stops, which became fricatives in old Germanic by Grimm's law. A few centuries later, the High German consonant shift led to a second series of lenitions in Old High German, chiefly of post-vocalic stops, as evidenced in the English-German cognates ripe, water, make vs. reifCategory:Articles containing German-language text, WasserCategory:Articles containing German-language text, machenCategory:Articles containing German-language text.

Although actually a much more profound change encompassing syllable restructuring, simplification of geminate consonants as in the passage from Latin to Spanish such as cuppa > /ˈkopa/Category:Pages with plain IPA 'cup' is often viewed as a type of lenition (compare geminate-preserving Italian /ˈkɔppa/Category:Pages with plain IPA).

Synchronic

Blocked lenition

Some languages which have lenition have in addition complex rules affecting situations where lenition might be expected to occur but does not, often those involving homorganic consonants. This is colloquially known as 'blocked lenition', or more technically as 'homorganic inhibition' or 'homorganic blocking'. In Scottish Gaelic, for example, there are three homorganic groups:^[5]

• d n t l s (usually called the dental group in spite of the non-dental nature of the palatals)
• c g (usually called the velar group)
• b f m p (usually called the labial group)

In a position where lenition is expected due to the grammatical environment, lenition tends to be blocked if there are two adjacent homorganic consonants across the word boundary. For example:^[5]

• aonCategory:Articles containing Scottish Gaelic-language text 'one' (which causes lenition) → aon chasCategory:Articles containing Scottish Gaelic-language text 'one leg' vs aon taighCategory:Articles containing Scottish Gaelic-language text 'one house' (not aon *thaighCategory:Articles containing Scottish Gaelic-language text)
• air anCategory:Articles containing Scottish Gaelic-language text 'on the' (which causes lenition) → air a' chas mhòrCategory:Articles containing Scottish Gaelic-language text 'on the big leg' vs air an taigh donnCategory:Articles containing Scottish Gaelic-language text "on the brown house" (not air an *thaigh *dhonnCategory:Articles containing Scottish Gaelic-language text)

In modern Scottish Gaelic this rule is only productive in the case of dentals but not the other two groups for the vast majority of speakers. It also does not affect all environments any more. For example, while aonCategory:Articles containing Scottish Gaelic-language text still invokes the rules of blocked lenition, a noun followed by an adjective generally no longer does so. Hence:^[5]

• adCategory:Articles containing Scottish Gaelic-language text "hat" (a feminine noun causing lenition) → ad dhonnCategory:Articles containing Scottish Gaelic-language text "a brown hat" (although some highly conservative speakers retain ad donnCategory:Articles containing Scottish Gaelic-language text)
• caileagCategory:Articles containing Scottish Gaelic-language text "girl" (a feminine noun causing lenition) → caileag ghlicCategory:Articles containing Scottish Gaelic-language text "a smart girl" (not caileag *glicCategory:Articles containing Scottish Gaelic-language text)

There is a significant number of frozen forms involving the other two groups (labials and velars) and environments as well, especially in surnames and place names:^[5]

• MacGumaraidCategory:Articles containing Scottish Gaelic-language text 'Montgomery' (macCategory:Articles containing Scottish Gaelic-language text + GumaraidCategory:Articles containing Scottish Gaelic-language text) vs MacDhòmhnaillCategory:Articles containing Scottish Gaelic-language text 'MacDonald (macCategory:Articles containing Scottish Gaelic-language text + DòmhnallCategory:Articles containing Scottish Gaelic-language text)
• CaimbeulCategory:Articles containing Scottish Gaelic-language text 'Campbell' (camCategory:Articles containing Scottish Gaelic-language text 'crooked' + beulCategory:Articles containing Scottish Gaelic-language text 'mouth') vs CamshronCategory:Articles containing Scottish Gaelic-language text 'Cameron' (camCategory:Articles containing Scottish Gaelic-language text + srònCategory:Articles containing Scottish Gaelic-language text 'nose')
• sgian-dubhCategory:Articles containing Scottish Gaelic-language text 'Sgian-dubh' (sgianCategory:Articles containing Scottish Gaelic-language text 'knife' + dubhCategory:Articles containing Scottish Gaelic-language text '1 black 2 hidden'; sgianCategory:Articles containing Scottish Gaelic-language text as a feminine noun today would normally cause lenition on a following adjective) vs sgian dhubhCategory:Articles containing Scottish Gaelic-language text "a black knife" (i.e., a common knife which just happens to be black)

Though rare, in some instances the rules of blocked lenition can be invoked by lost historical consonants, for example, in the case of the past-tense copula buCategory:Articles containing Scottish Gaelic-language text, which in Common Celtic had a final -t. In terms of blocked lenition, it continues to behave as a dental-final particle invoking blocked lenition rules:^[5]

• bu dona am biadhCategory:Articles containing Scottish Gaelic-language text "bad was the food" versus bu mhòr am beudCategory:Articles containing Scottish Gaelic-language text 'great was the pity

In Brythonic languages, only fossilized vestiges of lenition blocking occur, for example in Welsh nos daCategory:Articles containing Welsh-language text 'good night' lenition is blocked^[6] (nosCategory:Articles containing Welsh-language text as a feminine noun normally causes lenition of a following modifier, for example GwenerCategory:Articles containing Welsh-language text 'Friday' yields nos WenerCategory:Articles containing Welsh-language text 'Friday night'). Within Celtic, blocked lenition phenomena also occur in Irish (for example aon dorasCategory:Articles containing Irish-language text 'one door', an chéad duineCategory:Articles containing Irish-language text 'the first person') and Manx (for example un dorrysCategory:Articles containing Manx-language text 'one door', yn chied dooinneyCategory:Articles containing Manx-language text 'the first man') however.

Outside Celtic, in Spanish orthographic b d g are retained as [b, d, ɡ]Category:Pages with plain IPA following nasals rather than their normal lenited forms [β, ð, ɣ]Category:Pages with plain IPA.

Citations

General references

• Crowley, Terry (1997). An Introduction to Historical Linguistics. 3rd edition. Oxford University Press.
• Oftedal, Magne (1985). Lenition in Celtic and in Insular Spanish: The Secondary Voicing of Stops in Gran Canaria. Oxford University Press, USA. ISBN 8200072827.