I was wondering how the formally write the rule for assimilation; for example:


mp -> mm

ŋk -> ŋŋ

nt -> nn

lt -> ll

rt -> rr

I'm guessing it's assimilation when the preceeding consonant is a sonorant. (The above are all the examples I have in my data. Just not sure how to write the formal rule.

It assimilates from the nom sg to the Genitive, Nom pl, and ablative, BUT doesnt assimilate (it stays the same) when is the Essive sg form. Can anyone tell me why this is??

No rules seem to apply in the Essive from at all, just the addition of the suffix -na ~ -nae. How can I explain this in rules or otherwise?

  • 6
    This is a homework question.
    – user6726
    Sep 17, 2015 at 23:50
  • Here is a dissertation on complete assimilations that might be helpful: etd.ohiolink.edu/…
    – Greg Lee
    Sep 18, 2015 at 2:09
  • Welcome to Linguistics SE! In the essive, do you mean that the phonological context is the same, but assimilation doesn't happen? Sep 18, 2015 at 9:44
  • You can't really explain consonant gradation in Finnish by phonological rules alone, because it's not consistent. The historical origin is as user8017’s answer states, but sound changes and analogies have messed it up. /k/, for example, becomes null, but /v/ between high, rounded vowels (/u/ and /y/) and /j/ between an /r/ and a front vowel; some suffixes (like 3p possessive -nsA) close the syllable but do not affect gradation; and loss of some intervocalic consonants have turned earlier (open) V.CVC structures into (closed) VVC structures, which also does not affect gradation. Sep 20, 2015 at 10:31

2 Answers 2


The assimilation you mention is a special case of more general consonant lenition: e.g. täti ("aunt") has genitive singular din. This process of lenition only occurs in closed syllables.

The standard Finnish essive case suffix (-na/-nä) is of the form -CV, which cannot close the preceding syllable, because the C- is the onset of the following syllable.

Therefore, the essive suffix does not cause lenition: only suffixes that end in -C (like genitive singular -n) or that contain a -CC- cluster (like elative -sta/-stä) can cause it.

I am not sure what the usual formal notation is for the feature "closed/open syllable", and (if I'm not mistaken) you would need to include that in the formulation of this process of nasal assimilation. So, I'm afraid I can't answer that part of your question.


Here is an attempt at an SPE style rule (except that reference to the "." syllable boundary would not be allowed by SPE conventions):

[-son] -> [+son, alpha place, C] / [+son, alpha place, C] __ V C .

The main idea here is to get the features of the changed segment right by appealing to the markedness conventions of SPE's chapter 9. The changed segment is required to be a sonorant consonant which is homorganic to the preceding sonorant consonant, and the other features of this segment will have their unmarked values, as determined by the markedness conventions. For instance, we'll get [m] after [p] if [m] is the least marked sonorant labial consonant.

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