Editing Lenition (section)

=== 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:<ref name="Blas">{{cite book| last = Bauer| first = Michael| title = Blas Na Gāidhlig: The Practical Guide to Scottish Gaelic Pronunciation| year = 2011| publisher = Akerbeltz| isbn = 978-1-907165-00-9 }}</ref>
* d n t l s (usually called the [[Dental consonant|dental]] group in spite of the non-dental nature of the palatals)
* c g (usually called the [[Velar consonant|velar]] group)
* b f m p (usually called the [[Labial consonant|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:<ref name=Blas/>
* {{lang|gd|aon}} 'one' (which causes lenition) → {{lang|gd|aon chas}} 'one leg' vs {{lang|gd|ao'''n t'''aigh}} 'one house' (not {{lang|gd|aon *thaigh}})
* {{lang|gd|air an}} 'on the' (which causes lenition) → {{lang|gd|air a' chas mhòr}} 'on the big leg' vs {{lang|gd|air a'''n t'''aigh '''d'''onn}} "on the brown house" (not {{lang|gd|air an *thaigh *dhonn}})
In modern Scottish Gaelic this rule is only [[Productivity (linguistics)|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 {{lang|gd|aon}} still invokes the rules of blocked lenition, a noun followed by an adjective generally no longer does so. Hence:<ref name=Blas/>
* {{lang|gd|ad}} "hat" (a feminine noun causing lenition) → {{lang|gd|ad dhonn}} "a brown hat" (although some highly conservative speakers retain {{lang|gd|ad donn}})
* {{lang|gd|caileag}} "girl" (a feminine noun causing lenition) → {{lang|gd|caileag ghlic}} "a smart girl" (not {{lang|gd|caileag *glic}})
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:<ref name=Blas/>
* {{lang|gd|Ma'''cG'''umaraid}} 'Montgomery' ({{lang|gd|mac}} + {{lang|gd|Gumaraid}}) vs {{lang|gd|Ma'''cDh'''òmhnaill}} 'MacDonald ({{lang|gd|mac}} + {{lang|gd|Dòmhnall}})
* {{lang|gd|Cai'''mb'''eul}} 'Campbell' ({{lang|gd|cam}} 'crooked' + {{lang|gd|beul}} 'mouth') vs {{lang|gd|Ca'''msh'''ron}} 'Cameron' ({{lang|gd|cam}} + {{lang|gd|sròn}} 'nose')
* {{lang|gd|sgia'''n-d'''ubh}} '[[Sgian-dubh]]' ({{lang|gd|sgian}} 'knife' + {{lang|gd|dubh}} '1 black 2 hidden'; {{lang|gd|sgian}} as a feminine noun today would normally cause lenition on a following adjective) vs {{lang|gd|sgian dhubh}} "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 (linguistics)|copula]] {{lang|gd|bu}}, 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:<ref name=Blas/>
* {{lang|gd|bu '''d'''ona am biadh}} "bad was the food" versus {{lang|gd|bu '''mh'''òr am beud}} 'great was the pity

In Brythonic languages, only fossilized vestiges of lenition blocking occur, for example in Welsh {{lang|cy|no'''s d'''a}} 'good night' lenition is blocked<ref>{{cite web |url=https://core.ac.uk/download/pdf/151480254.pdf |title=Celtic initial consonant mutations – nghath and bhfuil? |last=Conroy |first=Kevin M  |date=2008 |website= |publisher=Boston College University Libraries |access-date=16 September 2021 |quote=}}</ref> ({{lang|cy|nos}} as a feminine noun normally causes lenition of a following modifier, for example {{lang|cy|Gwener}} 'Friday' yields {{lang|cy|nos Wener}} 'Friday night'). Within Celtic, blocked lenition phenomena also occur in Irish (for example {{lang|ga|ao'''n d'''oras}} 'one door', {{lang|ga|an chéa'''d d'''uine}} 'the first person') and [[Manx Gaelic|Manx]] (for example {{lang|gv|u'''n d'''orrys}} 'one door', {{lang|gv|yn chie'''d d'''ooinney}} 'the first man') however.

Outside Celtic, in [[Spanish language|Spanish]] orthographic b d g are retained as {{IPA|[b, d, ɡ]}} following nasals rather than their normal lenited forms {{IPA|[β, ð, ɣ]}}.