= 2.2.6. Blocked alternations

The following table shows the number of potentially alternating counterparts which do not alternate because both of them are/​one of them is prohibited (or at least strongly discouraged) in non-initial syllables. The number in the paranthesis shows the number of the potentially alternating but practically non-alternating pairs if short and long vowels are counted separately. 

^  ^ Finn. ^ Seto ^ Er. ^ HMr ^ MMr ^ Ud. ^ Hun. ^ SMn ^ SKh ^ VKh ^ Nga. ^ Ka. ^
^ F/B | 0 | 1 (5) | complicated | 2 | 1 | 2 | 0 | ? | 3 | 0 | 1 | 4 |
^ R%%|%%T | — | — | — | — | 1 | — | 2 (3) | ? | — | — | 1 | — |

<fs smaller>
F/B: front/back harmony\\
R|T: rounding, total harmony\\
—: not applicable</fs>

  ; Seto
  : /i/ : /ɨ/ is a potential alternating pair but /ɨ/ is prohibited in non-intitial syllables; all long vowels are prohibited in non-initial syllables

  ; Erzya
  : First of all, it can be questioned whether /u/ : / i/ is a potential alternation (see [[2.2.2.do_all_potential_counterparts_alternate|§2.2.2]]). If we consider that it is, the restriction on /u/ and that on /i/ are different. The vowel /u/ is practically prohibited in non-initial syllables and it never occurs in suffixes. Although the vowel /i/ is similarly rare in non-initial syllables, it occurs in suffixes, especially in verbal ones.  

  ; Hill Mari
  :  Rounded vowels are prohibited in non-inital syllables.

  ; Meadow Mari
  : Rounded vowels are practically prohibited in non-initial syllables, [ø] and [o] occur in word-final position due to rounding (and F/B) harmony as allophonic alternants of /ə̆/.  The alternation [e] : [ø] occurs in the same position. However, phonemic /e/ does not alternate due to VH.

  ; Udmurt
  : All rounded vowels but /o/ are prohibited in non-initial syllables (/o/ is quite frequent even in suffixes).  

  ; Hungarian 
  : **Rounding harmony:** Only short mid rounded vowel /ø/ alternates with high unrounded vowel /ɛ/, although they do not form a potential alternating pair due to the difference in height (cf. [[2.inventories:2.2.counterparts:2.2.4.irregular_alternations|§2.2.4.]]). High and long vowels do not undergo rounding harmony (there are no alternations /i/ : /y/, /iː/ : /yː/, /eː/ : /øː/), although any of these vowels can occur in non-initial syllables (at least in Standard Hungarian as it is reflected by orthography).

  ; Southern Khanty
  : Rounded vowels are prohibited in non-initial syllables.

  ; Vakh/Vasyugan Khanty
  : Although practically all rounded vowels are prohibited in non-initial syllables, alternations /o/ : /ø/  and /ø̆/ : /ŏ/ occur in one suffix, respectively. However, because in both suffixes the alternating vowels are followed by /ɣ/, it is questionable whether these are the rounded vowel phonemes or just rounded allophones of non-rounded ones. The latter assumption is especially problematic in the case of  the /o/ : /ø/ alternation, since full /e/ has no back counterpart. Moreover, non-alternating /u/ occurs in one suffix, but non-alternatin /y/ never occurs. (Cf. [[2.inventories/2.2.counterparts/2.2.2.do_all_potential_counterparts_alternate|§2.2.2]].)

  ; Nganasan
  : There could be an /e/ : /o/ alternation due to quasi-rounding harmony and /e/ : /ɘ/ alternation due to F/B harmony, but  /e/ and /o/ are practically prohibited in non-initial syllables and they never occur in suffixes.

  ; Kamas
  : Rounded vowel phonemes are practically prohibited in non-initial syllables (or at least in suffixes), although rounded allophones of the reduced vowel /ə̆/ (= /ĭ/ and/or /ɑ̆/) occur due to full harmony.