Editing Consonant gradation (section)

==Definition==
The term "consonant gradation" refers to a word-medial [[Alternation (linguistics)|alternation]] of consonants between [[fortis and lenis]] realisations. The fortis '''strong grade''' appears in historically open syllables (ending in a vowel), while the lenis '''weak grade''' appears in historically closed syllables (ending in a consonant). The exact realisation of the fortis–lenis distinction differs between the branches. In the Samic languages it was realised through [[fortition]], specifically lengthening, in the strong grade. In the Finnic and Samoyedic languages, there was instead [[lenition]] in the weak grade. Thus, the exact realization of the contrast is not crucial.

{| class="wikitable"
|+ Examples of consonant gradation
|-
! Language !! Alternation<br/>(strong : weak) !! Phonetic nature of alternation<br/>(strong : weak)
|-
| Estonian || {{lang|et|su'''kk'''}} : {{lang|et|su'''k'''-a}}<br/>{{IPA|/sukːː/}} : {{IPA|/sukːɑ/}} || [[Length (phonetics)|Length]]<br/>''overlong : long''
|-
| Finnish || {{lang|fi|su'''kk'''a}} : {{lang|fi|su'''k'''a-n}}<br/>{{IPA|/sukːɑ/}} : {{IPA|/sukɑn/}} || Length<br/>''long : short''
|-
| Estonian || {{lang|et|ai'''t'''}} : {{lang|et|ai'''d'''-a}}<br/>{{IPA|/ɑit/}} : {{IPA|/ɑid̥ɑ/}} || [[Fortis and lenis|Tenseness]]<br/>''tense voiceless : lax voiceless''
|-
| Finnish || {{lang|fi|ai'''t'''a}} : {{lang|fi|ai'''d'''a-n}}<br/>{{IPA|/ɑitɑ/}} : {{IPA|/ɑidɑn/}} || [[Voice (phonetics)|Voicing]]<br/>''voiceless : voiced''
|-
| Finnish || {{lang|fi|lam'''p'''i}} : {{lang|fi|lam'''m'''e-n}}<br/>{{IPA|/lɑmpi/}} : {{IPA|/lamːen/}} || [[Manner of articulation]]<br/>''stop : nasal''
|-
| Karelian || {{lang|krl|muš'''t'''a}} : {{lang|krl|muš'''š'''a-n}}<br/>{{IPA|/muʃtɑ/}} : {{IPA|/muʃːɑn/}} || Manner of articulation<br/>''stop : fricative''
|-
| Finnish || {{lang|fi|kyl'''k'''i}} : {{lang|fi|kyl'''j'''e-n}}<br/>{{IPA|/kylki/}} : {{IPA|/kyljen/}} || Manner of articulation<br/>''stop : semivowel''
|-
| Nganasan || {{lang|nio|ба'''х'''и}} : {{lang|nio|ба'''б'''и}}<br/>{{IPA|/bahi/}} : {{IPA|/babi/}} || Voicing + manner and [[place of articulation]]<br/>''voiceless glottal fricative : voiced bilabial stop''
|-
| Finnish || {{lang|fi|te'''k'''o}} : {{lang|fi|teon}}<br/>{{IPA|/teko/}} : {{IPA|/te.on/}} || Presence of segment<br/>''stop : [[Zero (linguistics)|zero]]''
|-
| Northern Sami || {{lang|se|Sá'''pm'''i}} : {{lang|se|Sá'''m'''i}}<br/>{{IPA|/saːp.miː/}} : {{IPA|/saː.miː/}} || Presence of segment<br/>''pre-stopped nasal : plain nasal''
|-
| Northern Sami || {{lang|se|die'''ht'''aga}} : {{lang|se|die'''đ'''a}}<br/>{{IPA|/tie̯h.ta.ka/}} : {{IPA|/tie̯.ða/}} || Presence of segment + articulation<br/>''preaspirated stop : fricative''
|-
| Northern Sami || {{lang|se|dea'''dj'''a}} : {{lang|se|dea'''j'''a}}<br/>{{IPA|/tea̯c.ca/}} : {{IPA|/tea̯.ja/}} || Manner of articulation<br/>''stop : semivowel''
|-
| Northern Sami || {{lang|se|ruo'''kt'''u}} : {{lang|se|ruo'''vtt'''u}}<br/>{{IPA|/ruo̯kː.tuː/}} : {{IPA|/ruo̯vt.tuː/}} || Length + articulation<br/>''long stop + singleton : short semivowel + geminate''
|-
| Northern Sami || {{lang|se|ba'''st'''e}} : {{lang|se|ba'''stt'''e}}<br/>{{IPA|/pasː.te/}} : {{IPA|/pas.te/}} || Length<br/>''long : short''
|-
| Nganasan || {{lang|nio|ко'''ӈх'''у}} : {{lang|nio|ко'''мб'''у}}<br/>{{IPA|/koŋhu/}} : {{IPA|/kombu/}} || Voicing + manner and place of articulation<br/>''velar nasal + voiceless glottal fricative : bilabial nasal + voiced bilabial  stop''
|}

The language groups differ in regard to their treatment sequences of a vowel followed by ''j'' or ''w'' in Proto-Uralic. In the Samic languages, the second part of these remains phonologically a consonant, and can thus close the syllable before it, triggering the weak grade. It also takes part in gradation itself, lengthening in the strong grade. In Finnic, on the other hand, these were treated as diphthongs, and were equivalent to long vowels in terms of syllable structure. Consequently, they did not close the syllable and did not affect gradation.

Consonant gradation is understood to have originally been a predictable [[phonological process]]. In all languages that retain it, however, it has evolved further to a less predictable system of [[consonant mutation]], of [[morphophonological]] or even purely [[Morphology (linguistics)|morphological]] nature. This is a consequence of later changes in the structure of syllables, which made closed syllables open or vice versa, without adjusting the gradation. For example, in Northern Sami, the only difference between {{lang|se|giella}} and {{lang|se|giela}} ('language', nominative and genitive singular respectively) is the grade; the final consonant that originally closed the syllable in the genitive form, namely ''-n'', has disappeared (the same happened in the history of Estonian and Nganasan). Even in Finnish, which is relatively conservative with respect to consonants, there are many cases of strong grades in closed syllables and weak grades in open syllables, e.g. {{lang|fi|sade}} and {{lang|fi|sateen}} ('rain', nominative and genitive singular). These, again, are the result of changes in syllable structure, with the original Proto-Finnic ''*sadek'' and ''*sategen'' following the rules more obviously. In addition, not all Finnish words that hypothetically could have gradation undergo it: for instance, the genitive form of {{lang|fi|auto}} 'car' is {{lang|fi|auton}}. Thus, the occurrence of gradation is not  morphologically predictable anymore, it is a property of each individual word.