Consonant gradation
Encyclopedia
Consonant gradation is a type of consonant mutation
Consonant mutation
Consonant mutation is when a consonant in a word changes according to its morphological and/or syntactic environment.Mutation phenomena occur in languages around the world. A prototypical example of consonant mutation is the initial consonant mutation of all modern Celtic languages...

, in which consonants alternate
Alternation (linguistics)
In linguistics, an alternation is the phenomenon of a phoneme or morpheme exhibiting variation in its phonological realization. Each of the various realizations is called an alternant...

 between various "grades". It is found in some Uralic languages
Uralic languages
The Uralic languages constitute a language family of some three dozen languages spoken by approximately 25 million people. The healthiest Uralic languages in terms of the number of native speakers are Hungarian, Finnish, Estonian, Mari and Udmurt...

 such as Finnish
Finnish language
Finnish is the language spoken by the majority of the population in Finland Primarily for use by restaurant menus and by ethnic Finns outside Finland. It is one of the two official languages of Finland and an official minority language in Sweden. In Sweden, both standard Finnish and Meänkieli, a...

, Estonian
Estonian language
Estonian is the official language of Estonia, spoken by about 1.1 million people in Estonia and tens of thousands in various émigré communities...

, Northern Sámi
Northern Sami
Northern or North Sami is the most widely spoken of all Sami languages. The speaking area of Northern Sami covers the northern parts of Norway, Sweden and Finland...

, and the Samoyed language Nganasan
Nganasan language
Nganasan language is a language of the Nganasan people...

. In addition, it has been reconstructed for Proto-Germanic, the parent language of the Germanic languages. Of the Finnic languages
Finnic languages
The term Finnic languages often means the Baltic-Finnic languages, an undisputed branch of the Uralic languages. However, it is also commonly used to mean the Finno-Permic languages, a hypothetical intermediate branch that includes Baltic Finnic, or the more disputed Finno-Volgaic languages....

, Votic
Votic language
Votic or Votian is the language spoken by the Votes of Ingria. It is closely related to Estonian and belongs to the Finnic subgroup of Uralic languages. Votic is spoken only in Krakolye and Luzhitsy, two villages in the Kingisepp district, and is close to extinction...

 is known for its extensive set of gradation patterns. Consonant gradation in some of these languages is not (or is no longer) purely phonological, although this may be surmised for various reconstructions of Proto-Finnic. In archiphonemic terms, the mutation is a type of lenition
Lenition
In linguistics, lenition is a kind of sound change that alters consonants, making them "weaker" in some way. The word lenition itself means "softening" or "weakening" . Lenition can happen both synchronically and diachronically...

 in which there are quantitative (e.g. /kː/ vs. /k/) as well as qualitative (e.g. /k/ vs. /v/) alternations.

What types of consonants and consonant clusters may undergo gradation vary from language to language; for example, Northern Sámi
Northern Sami
Northern or North Sami is the most widely spoken of all Sami languages. The speaking area of Northern Sami covers the northern parts of Norway, Sweden and Finland...

 has three different grades (as well as having three quantities of consonant length), and also allows for quantitative gradation of its sonorants /l m n r/. Most Finnic languages
Finnic languages
The term Finnic languages often means the Baltic-Finnic languages, an undisputed branch of the Uralic languages. However, it is also commonly used to mean the Finno-Permic languages, a hypothetical intermediate branch that includes Baltic Finnic, or the more disputed Finno-Volgaic languages....

, however, have two grades and only allow stops to undergo gradation. Languages may also have other constraints for loanwords; for example, loan words and some personal names in Finnish may have quantitative gradation, but not qualitative, thus auto does not become *audon '(the) car's', but remains auton.

Finno-Lappic languages

Consonant gradation in the Finno-Lappic languages was originally triggered when the consonant appeared at the beginning of a closed syllable. A syllable was closed if it ended in a consonant, which in particular always occurred with a word-final consonant, but also if vowels were separated by two or more consonants (including geminates). The effect of gradation was a lenition
Lenition
In linguistics, lenition is a kind of sound change that alters consonants, making them "weaker" in some way. The word lenition itself means "softening" or "weakening" . Lenition can happen both synchronically and diachronically...

 of the consonant at the beginning of the syllable. Lenition caused geminate (long) stops to shorten, and it caused already-short voiceless obstruents to become voiced if they were not preceded by another obstruent:
  • pp -> p
  • tt -> t
  • kk -> k
  • p -> b
  • t -> d
  • k -> g
  • s -> z


The weakened grades soon underwent further changes. In particular, the voiced stops became fricatives unless they were preceded by a nasal consonant, and z became h. Many of the weak grades disappeared or assimilated in the later languages.

The weakened grades of geminate consonants still counted as geminates for the purposes of syllabification. That is, a syllable ending with a geminate in the weak grade was still considered "closed". One such example of these is the derivational suffix -ton/tön '-less'. When applied to the word tapa 'custom, practice', one would expect *tapaton when in fact it is tavaton. Historically this suffix was *-ttoin/ttöin, with a long -tt-. When gradation was introduced, this was not immediately fully shortened, but remained for a period an intermediate quantity, *-ťt-. This mid-length consonant was still able to trigger gradation of the root, and when they were changed to be realized as a short the effects on gradation remained, thus: *tapattoin → *tabaťtointavaton. This change is also the cause for the present surface forms of the Finnish passive.

However, consonant gradation was not the only source of voiced consonants in early Finnic. There was also other alternation pattern, based on stress rather than syllable structure. If a strong-grade consonant appeared between two unstressed vowels, it was changed into the weak grade. For example, in Finnish, the active present participle used to have an alternation of strong-grade -pa/-pä vs. weak-grade -va/-vä depending on whether or not it followed a stressed syllable, thus: saapa mies vs. istuva mies. Although this is not consonant gradation in the sense described above, these changes are still often treated under the same guise. If a distinction is desired, the usual sense can be called radical gradation.

Finnish

Finnish preserves the original system reasonably intact, although many later sound changes have obscured this. In particular:
  • b > v elsewhere
    • mb > mm
  • d > ? (varying pronunciations in modern dialects, still written d)
    • nd > nn
    • ld > ll
    • rd > rr
  • g > Ø (disappears)
    • ng > ŋŋ (still written ng)
    • lgi/lge > lji/lje
    • rgi/rge > rji/rje
    • ugu/ygy > uvu/yvy
  • h > Ø (disappears) between two unstressed short vowels (but not after a long vowel or diphthong, cf. illative plurals in -oihin)
  • d > Ø (disappears) between two unstressed short vowels (but not after a long vowel or diphthong, cf. verbs in -oida)
    • id > j instead
  • k > Ø (disappears) at the end of a word


These last changes did not spread across all of the Finnish language area. The Karelian dialects of Finnish, and indeed some dialects of the Karelian language do not always delete the intervocalic 'd'. Some dialects also preserve h.

Overview

Generally speaking, the nominative of the noun, and the first infinitive of verbs are most often in the "strong" grade. On the other hand, there are a few classes of nouns and verbs in which these "dictionary forms
Citation form
In linguistics the citation form of a word can mean:* its canonical form or lemma: the form of an inflected word given in dictionaries or glossaries, thus also called the dictionary form....

" of the words exhibit a weak grade. The process is grammatical, and it always works such that the "stem" of the word is the strong form. This sometimes creates difficulties in identifying the root (if the word is derived), because often seemingly basic words turn out to be derived, applying gradation in the process. For example, hake "wood chippings" gradates to hakkee-, not to *hae-, because it is already a gradated form of hakkaa- < "hack" (whose infinitive is the weak grade haka|ta). However, hake|a "to get, to search" does gradate to hae-, as hake- is the original form.
Quantitative Example Qualitative Example
pp → p kauppa ~ kaupan p → *b (v, chroneme
Chroneme
In linguistics, a chroneme is a basic, theoretical unit of sound that can distinguish words by duration only of a vowel or consonant. The noun chroneme is derived from Greek χρονος , and the suffixed -eme, which is analogous to the -eme in phoneme...

)
kalpa ~ kalvan
kk → k tikka ~ tikan k → *g (k, j, v, Ø; chroneme
Chroneme
In linguistics, a chroneme is a basic, theoretical unit of sound that can distinguish words by duration only of a vowel or consonant. The noun chroneme is derived from Greek χρονος , and the suffixed -eme, which is analogous to the -eme in phoneme...

)
ikä ~ iän
tt → t matto ~ maton t → *d (d*, chroneme
Chroneme
In linguistics, a chroneme is a basic, theoretical unit of sound that can distinguish words by duration only of a vowel or consonant. The noun chroneme is derived from Greek χρονος , and the suffixed -eme, which is analogous to the -eme in phoneme...

)
mato ~ madon


The realization of *d varies from dialect to dialect, some dialects deleting it, or some representing it as [r], [l], [ð], [h] or [j], or a combination of these. In eastern dialects, for instance, it is possible to find *d surfacing as either [h], [j] based on phonetic environment.

Since the phonetic environment controls the realization, the number of actual patterns is large. Assimilation
Assimilation (linguistics)
Assimilation is a common phonological process by which the sound of the ending of one word blends into the sound of the beginning of the following word. This occurs when the parts of the mouth and vocal cords start to form the beginning sounds of the next word before the last sound has been...

 produces a geminate, e.g. lampi 'pond' → lammen 'pond-Gen' (*lamben). Without the historical perspective mentioned above, this phoneme is analyzed as a chroneme
Chroneme
In linguistics, a chroneme is a basic, theoretical unit of sound that can distinguish words by duration only of a vowel or consonant. The noun chroneme is derived from Greek χρονος , and the suffixed -eme, which is analogous to the -eme in phoneme...

, a consonant exhibited as a lengthening of the previous consonant.

In terms of the standard language, K is the phoneme with the most possible changes. It can disappear as in jalka 'foot' → jalan 'foot-Gen', or:
Environment Change Strong Weak
-uku-
-yky-
kv puku puvun
-lki-
-rki-
kj kylki
järki
kyljen
järjen
-nk-
/ŋk/
/k/→/ŋ/ sänky
/säŋky/
sängyn
/säŋŋyn/


Changes for t include t : d (tietää : tiedän), rt : rr (kertoa : kerron), lt : ll (pelto : pellon), and nt ~ nn (antaa ~ annan). The last three forms are due to assimilation, rather than the consonant gradation itself. Changes for p include p : v (tapa : tavan) and mp : mm (lampi : lammen), where the latter is again caused by assimilation and not by consonant gradation itself. The quantitative consonant gradation, ie. kk : k, pp : p, tt : t, gg : g, dd : d and bb : b affects all geminates, and single consonants in inverse consonant gradation position.

Due to the agglutinative nature of Finnic languages, and thus the application of a number of derivational suffixes, there are various grade alternations that occur in suffixes, not just word roots. An intensitive/causatival verbal suffix -tta/ttä- undergoes gradation to -ta/tä- when various derivational or inflectional suffixes are added to it, however when affixed to a word it also causes gradation in the inflectional stem. Thus, pitää 'to hold, keep' becomes pidättää 'to restrain, prevent, arrest'. When the word's syllable structure changes due to inflection for person and tense however, the grade of the previous stem does not change, as weakened geminates also trigger the weak grade on a preceding syllable: pidättää vs. pidätän 'I restrain'.

In modern Finnish, only quantitative gradation is still productive, and still applied to newly formed words. In loanwords, geminate voiced plosives (bb, dd, gg) behave much like their unvoiced counterparts, e.g. diggaa-digata "to dig, to like (something)".

In Finnish, consonant gradation does not apply to clusters such as -tk- (e.g. katkoa ~ katkon), -sp- (piispa ~ piispan) or -st- (lasta ~ lastan). However, it does apply to -ht- in many cases.

The effect of historical sound changes

Some of the problems with viewing consonant gradation as purely an issue of syllable structure (at least with the case of Finnish) is that the language has undergone various phonetic changes that mean that not all closed syllables exhibit a weak grade, and not all open syllables exhibit a strong grade. One important change was the loss of word-final -k early on in the history of Finnish.

The loss of final -k affected many words, although it survived marginally as an assimilative 'consonant' ˣ, which lengthens the first consonant of the next syllable. Its loss caused many open syllables with weak grades. In particular, the many nouns ending in -e are affected by this, with a weak grade in the nominative form. The imperative form of verbs also ends in a now-lost -k. For example, hakea "to get" > hae! "get! (imp.)" from *hage, earlier *hagek.

The loss of -k combined with loss of d were responsible for the modern Finnish infinitive ending, which was historically *-tak/täk. The final *-k triggered gradation, so that the ending normally became *-dak/däk. In turn, following the loss of d between unstressed vowels, and the loss of final *-k only *-aˣ/äˣ remained. Thus, hakea (originally *hakedak) has only -a as the d was lost. But juoda "to drink" kept its d because of the stressed syllable preceding it. In the case of tulla "to come", the earlier form was *tuldak, but the d was assimilated to the l according to the rules above. The original strong grade was preserved in haista "to stink" because of the preceding obstruent s which prevented gradation.

The situation appears differently in the many verbs ending in -ata/ätä. These verbs seem to have preserved the strong grade in the infinitive ending, going counter to the rules of gradation. However, historically it is in fact a weak grade: the stem of the verb itself ended in *-at/ät-, and this is still visible in the imperative ending -atkoon/ätköön. Thus, when combined with the infinitive ending, the verb ended in *-attak/ättäk (similar to the origin of the -ton/tön suffix described above). The -k then weakened the consonant from a geminate *-tt- to a single *-t-, and later loss of -k resulted in the final form -ata/ätä. However, even though this is now a single consonant, it was originally a geminate and therefore triggers the weak grade on the syllable before it. So whereas the infinitive may be for example hypätä "to jump", its original stem was *hyppät-, as can be seen in the first-person singular form hyppään "I jump", from earlier *hyppäden with loss of -d-.

Indirectly the partitive case
Partitive case
The partitive case is a grammatical case which denotes "partialness", "without result", or "without specific identity". It is also used in contexts where a subgroup is selected from a larger group, or with numbers....

, which was historically *-ta/tä, was also affected, but in a different way because it did not end in a consonant as the infinitive originally did. This suffix therefore only shows gradation after unstressed syllables, where it was weakened to *-da/dä, after which the -d- was lost so that the suffix is now just -a/ä for many words. Thus, maa "land" has the partitive maata with the original -ta, which did not weaken as it stood after a stressed syllable. But the noun kylä "village" has the partitive kylää, from earlier *kylädä, even earlier *kylätä.

Loss of h between unstressed vowels affected nouns and adjectives ending in -s, such as kuningas "king". In the nominative, this -s appeared as usual, and as the preceding syllable was closed, the weak grade ng appeared. But when a case ending such as the genitive -(e)n was added, the result was originally *kuninkasen, which was then weakened to *kuninkahen, and the loss of -h- then resulted in the modern form *kuninkaan. The same happened in mies "man", but the -h- was not lost, so that its genitive is miehen.

Similar changes affected the illative ending, which was -hVn where V was the same as the vowel preceding the ending. The h is preserved after stressed syllables, as in maahan "into the land" (from maa), but lost otherwise as in kotiin "into the home" (from earlier *kotihin, from koti). This explains why kotiin retains a strong grade even though a closed syllable follows it. The Pohjanmaa dialect of Finnish retains the -h-, however.

Words that now end in -e are in fact very similar to those ending in -s. These originally ended with -k as the infinitive, so that the nominative ended in a consonant just as kuningas and therefore the preceding syllable was in the weak grade. But after an ending was added, the weak grade g appeared, which eventually disappeared just as h did.

Karelian

Karelian
Karelian language
Karelian language is a Finnic language spoken mainly in the Russian Republic of Karelia. Linguistically Karelian is closely related to the Finnish dialects spoken in eastern Finland and some Finnish linguists even classified Karelian as a dialect of Finnish...

 consonant gradation is quite similar to Finnish, as a result of the two being closely related languages. On the other hand, Karelian includes some gradation pairs which Finnish does not. Karelian, unlike Finnish, allows the consonants /t k/ to undergo consonant gradation when following /s/ or /š/: muistua 'to remember' → muissan 'I remember'. On the other hand, some Karelian dialects (such as Livvi or Olonets) do not allow for gradation between clusters beginning on nasals. Thus, the Olonets Karelian equivalent of Finnish vanhemmat (> vanhempi 'older') is vahnembat.

The Karelian phoneme inventory also includes the affricate /tʃ/ (represented in the orthography as č, which may be found geminated and is such subject to quantitative gradation: meččä 'forest' → mečäššä 'in (the) forest'.

Votic

Votic has two quantities for consonants and vowels, which basically match up with the Finnish counterparts. The Votic phoneme inventory includes a set of fully voiced stops, which Paul Ariste
Paul Ariste
Paul Ariste was an Estonian linguist renowned for his studies of the Finno-Ugric languages , Yiddish and Baltic Romani language. He was born as Paul Berg, but in 1927 Estonized his name to Ariste. He graduated from the University of Tartu and subsequently worked with it...

 (A Grammar of the Votic Language) describes as being the same as in Russian. Thus, in addition to quantitative alternations between /p: t: k:/ and /p t k/, Votic also has a system of qualitative alternations in which the distinguishing feature is voicing and so the voiceless stops /p t k/ are known to alternate with /b d g/. These stops also alternate in clusters, which is (for the most part) not found in Finnish.
Qualitative Alternations  
hkhg tuhkatuhgassa
'ash' → 'from (the) ash'
ŋkŋg aŋkoaŋgō
'pitchfork' → 'pitchfork (gen.)'
skzg pǟskopǟzgō
'swallow' → 'swallow (gen.)'
šk /ʃk/ → žg /ʒɡ/ šiškašižgā
'rag' → 'rag (gen.)'
tšk /tʃk/ → džg /dʒɡ/ botškabodžgad
'barrel' → 'barrels'
sz isä → izässä
'father' → 'from (the) father'


Votic also has a number of alternations between continuant
Continuant
A continuant is a sound produced with an incomplete closure of the vocal tract. That is, any sound except a stop or nasal. An affricate is considered to be a complex segment, composed of both a stop and a continuant.-See also:...

s which are short in the 'weak' grade, and geminates in the 'strong' grade (kassā 'to sprinkle/water' vs. kasan 'I sprinkle/water'), as well as more voicing alternations between palatalized
Palatalization
In linguistics, palatalization , also palatization, may refer to two different processes by which a sound, usually a consonant, comes to be produced with the tongue in a position in the mouth near the palate....

 stops, and the alternations between nasal+consonant~nasal+chroneme found in Finnish. Votic also includes alternations in which the 'strong' grade is represented by a short consonant, while the 'weak' grade is represented by a geminate: rite̮le̮n vs. riďďe̮lla. For comparison, the Finnish equivalents of these is riitelen 'I quarrel' vs. riidellä 'to quarrel'.

Northern Sámi

Northern Sámi has a system of three phonological lengths for consonants, and thus has extensive sets of alternations. Not just stops and affricates are subject to gradation, but in addition sonorant
Sonorant
In phonetics and phonology, a sonorant is a speech sound that is produced without turbulent airflow in the vocal tract; fricatives and plosives are not sonorants. Vowels are sonorants, as are consonants like and . Other consonants, like or , restrict the airflow enough to cause turbulence, and...

s and fricatives. Sonorants and fricatives are only subject to quantitative gradation, but stops and affricates are subject to both quantitative and qualitative changes. Some words alternate between three grades, though not all words do. Note that the following apostrophe marking the over-long grade is not used in the official orthography, although it is generally found in dictionaries.

Some gradation triads include the following:
Continuants Over-long long short
/ð/ đ'đ
oađ'đi
'sleeper'
đđ
oađđit
'to sleep'
đ
oađán
'I sleep'
/r̥/ hr'r
skuhr'ri
'snorer'
hrr
skuhrrat
'to snore'
hr
skuhrai
'S/he snored'
/m/ m'm
cum'má
'kiss'
mm
cummát
'kisses'
m
namma ~ namat
'name' ~ 'names'
/s/ s's
guos'si
'guest'
ss
guossit
'guests'
s
viessu ~ viesut
'house' ~ 'houses'

Stops Over-long long short
/p/ hpp /hːp/ hp /hp/ b /b/~/v/
b'b /bːp/ pp /pː/  
/t/ htt /hːt/ ht /ht/ đ /ð/
d'd /dːt/ tt /tː/  
/k/ hkk /hːk/ hk /hk/ g /k/~/∅/
g'g /ɡːk/ kk /kː/  
/tʃ/ hčč /hːtʃ/ /htː/ ž /tʃ/
ž'ž /dːtʃ/ čč /tʃː/  
/ts/ hcc /h:ts/ hc /hts/ z /ts/
z'z /dːts/ cc /tːs/  



North Sámi also has phonotactic rules which provide for more consonant clusters, which are also subject to alternation. In some dialects the syllable structure is what is alternating, not necessarily consonant length or quality. For example, the word bárdni 'boy' contains a schwa vowel between the r and d, but only in the "strong" form of the word, and is lost when the word alternates: /pærᵊtniː/ ~ /pærtniːʰt/ 'boys'.

Nganasan

Nganasan
Nganasan language
Nganasan language is a language of the Nganasan people...

, alone of the Samoyedic languages (or indeed any Uralic languages east of Finnic), shows systematic qualitative gradation of stops
Stop consonant
In phonetics, a plosive, also known as an occlusive or an oral stop, is a stop consonant in which the vocal tract is blocked so that all airflow ceases. The occlusion may be done with the tongue , lips , and &...

 and fricatives
Fricative consonant
Fricatives are consonants produced by forcing air through a narrow channel made by placing two articulators close together. These may be the lower lip against the upper teeth, in the case of ; the back of the tongue against the soft palate, in the case of German , the final consonant of Bach; or...

. Gradation occurs in intervocalic position as well as in consonant cluster
Consonant cluster
In linguistics, a consonant cluster is a group of consonants which have no intervening vowel. In English, for example, the groups and are consonant clusters in the word splits....

s consisisting of a nasal
Nasal consonant
A nasal consonant is a type of consonant produced with a lowered velum in the mouth, allowing air to escape freely through the nose. Examples of nasal consonants in English are and , in words such as nose and mouth.- Definition :...

 and a stop
Stop consonant
In phonetics, a plosive, also known as an occlusive or an oral stop, is a stop consonant in which the vocal tract is blocked so that all airflow ceases. The occlusion may be done with the tongue , lips , and &...

. Examples of Nganasan consonant gradation can be seen in the following table (the first form given is always the nominative
Nominative case
The nominative case is one of the grammatical cases of a noun or other part of speech, which generally marks the subject of a verb or the predicate noun or predicate adjective, as opposed to its object or other verb arguments...

 singular, the latter the genitive
Genitive case
In grammar, genitive is the grammatical case that marks a noun as modifying another noun...

 singular):
Gradation Example Gloss
h : b bahi : babi 'wild reindeer'
t : ð ŋuta : ŋuða 'berry'
k : ɡ məku : məɡu 'back'
s : dʲ basa : badʲa 'iron'
ŋh : mb koŋhu : kombu 'wave'
nt : nd dʲintə : dʲində 'bow'
ŋk : ŋɡ bəŋkə : bəŋɡə 'sod hut'
ns : nʲdʲ bənsə : bənʲdʲə 'all'

Proto-Germanic

Outside the Uralic family, the term consonant gradation has recently been applied to Proto-Germanic, the parent language of the Germanic languages. Consonant gradation is not directly attested in any of the Germanic dialects, but must nevertheless be reconstructed on the basis of certain dialectal discrepancies in root of the n-stems and the ōn-verbs.

Diachronically, the rise of consonant gradation in Germanic is explained by Kluge's law
Kluge's Law
Kluge's Law is a Proto-Germanic sound law formulated by Friedrich Kluge. It describes the assimilation of an n to a preceding voiced consonant, under the condition that the n was part of a suffix which was accented in Proto-Indo-European . This law explains the origin of the Proto Germanic...

, by which geminates arose from stops followed by a nasal in a stressed syllable. Since this sound law only operated in part of the paradigms of the n-stems and ōn-verbs, it gave rise to an alternation of geminated and non-geminated consonants.
n-stems PIE PGM
nominative C_́C-ōn C_C-ō
genitive C_C-n-ós C_CC-az

neh2-presents PIE PGM
3p. singular C_C-néh2-ti C_CC-ōþi
3p. plural C_C-nh2-énti C_G-unanþi


The reconstruction of grading paradigms in Proto-Germanic explains root alternations such as Old English steorra 'star' < *sterran- vs. Old Frisian stera 'id.' < *steran- and Norwegian (dial.) guva 'to swing' < *gubōn- vs. Middle High German gupfen 'id.' < *guppōn- as generalizations of the original allomorphy. In the cases concerned, this would imply reconstructing an n-stem nom. *sterō, gen. *sterraz < PIE *h2stér-ōn, *h2ster-n-ós and an ōn-verb 3sg. *guppōþi, 3pl. *gubunanþi < *ghubh-néh2-ti, *ghubh-nh2-énti.

External links

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