Finnish phonology

The table below lists the conventionally postulated diphthongs in Finnish. In speech (i.e. phonetically speaking) a diphthong does not sound like a sequence of two different vowels; instead, the sound of the first vowel gradually glides into the sound of the second one with full vocalization lasting through the whole sound. That is to say, the two portions of the diphthong are not broken by a pause or stress pattern. In Finnish, diphthongs are considered phonemic units, contrasting with both long vowel and short vowels. Phonologically, however, Finnish diphthongs usually are analyzed as sequences (this in contrast to languages like English, where the diphthongs are best analyzed as independent phonemes).

Diphthongs ending in i can occur in any syllable, but those ending in rounded vowels usually occur only in initial syllables, and rising diphthongs are confined to that syllable. It is usually taught that diphthongization occurs only with the combinations listed. However, there are recognized situations in which other vowel pairs diphthongize. For example, in rapid speech the word yläosa ('upper part', from ylä-, 'upper' + osa, 'part') can be pronounced [ˈylæo̯sɑ] (with the diphthong /æo̯/). The usual pronunciation is [ˈylæ.ˌosɑ] (with those vowels belonging to separate syllables).

The diphthongs [ey̯] and [iy̯] are quite rare and mostly found in derivative words, where a derivational affix starting with /y/ (or properly the vowel harmonic archiphoneme /U/) fuses with the preceding vowel, e.g. pimeys 'darkness' from pimeä 'dark' + /-(U)US/ '-ness' and siistiytyä 'to tidy up oneself' from siisti 'tidy' + /-UTU/ (a kind of middle voice) + /-(d)A/ (infinitive suffix). Older /*ey̯/ and /*iy̯/ in initial syllables have been shifted to [øy̯] and [yː].

Opening diphthongs are in standard Finnish only found in root-initial syllables like in words tietää 'to know', takapyörä 'rear wheel' (from taka- 'back, rear' + pyörä 'wheel'; the latter part is secondarily stressed) or luo 'towards'. This might make them easier to pronounce as true opening diphthongs [uo̯, ie̯, yø̯] (in some accents even wider opening [uɑ̯, iɑ̯~iæ̯, yæ̯][lower-alpha 1]) and not as centering diphthongs [uə̯, iə̯, yə̯], which are more common in the world's languages. The opening diphthongs come from earlier doubled mid vowels: /*oo/ > [uo̯], /*ee/ > [ie̯], /*øø/ > [yø̯]. Since that time new doubled mid vowels have come to the language from various sources.

Among the phonological processes operating in Finnish dialects are diphthongization and diphthong reduction. For example, Savo Finnish has the phonemic contrast of /ɑ/ vs. /uɑ̯/ vs. /ɑɑ/ instead of standard language contrast of /ɑ/ vs. /ɑɑ/ vs. /ɑu̯/.

A diagram illustrating the vowel groups in Finnish.

Finnish, like many other Uralic languages, has the phenomenon called vowel harmony, which restricts the cooccurrence in a word of vowels belonging to different articulatory subgroups. Vowels within a word "harmonize" to be either all front or all back.[8] In particular, no native noncompound word can contain vowels from the group {a, o, u} together with vowels from the group {ä, ö, y}. Vowel harmony affects inflectional suffixes and derivational suffixes, which have two forms, one for use with back vowels, and the other with front vowels. Compare, for example, the following pair of abstract nouns: hallitus 'government' (from hallita, 'to reign') versus terveys 'health' (from terve, healthy).

There are exceptions to the constraint of vowel harmony. For one, there are two front vowels that lack back counterparts: /i/ and /e/. Therefore, words like kello 'clock' (with a front vowel in a non-final syllable) and tuuli 'wind' (with a front vowel in the final syllable), which contain /i/ or /e/ together with a back vowel, count as back vowel words; /i/ and /e/ are effectively neutral in regard to vowel harmony in such words.[9] Kello and tuuli yield the inflectional forms kellossa 'in a clock' and tuulessa 'in a wind'. In words containing only neutral vowels, front vowel harmony is used, e.g. tie – tiellä ('road' – 'on the road'). For another, compound words do not have vowel harmony across the compound boundary;[10] e.g. seinäkello 'wall clock' (from seinä, 'wall' and kello, 'clock') has back /o/ cooccurring with front /æ/. In the case of compound words, the choice between back and front suffix alternants is determined by the immediately-preceding element of the compound; e.g. 'in a wall clock' is seinäkellossa, not *seinäkellossä.

A particular exception appears in a standard Finnish word, tällainen ('this kind of'). Although by definition a singular word, it was originally a compound word that transitioned over time to a more compact and easier form: tämänlajinen (from tämän, 'of this' and lajinen, 'kind') → tänlainen → tällainen, and further to tällä(i)nen for some non-standard speech.

New loan words may exhibit vowel disharmony; for example, olympialaiset ('Olympic games') and sekundäärinen ('secondary') have both front and back vowels. In standard Finnish, these words are pronounced as they are spelled, but many speakers apply vowel harmony – olumpialaiset, and sekundaarinen or sekyndäärinen.

Traditionally, /b/ and /ɡ/ were not counted as Finnish phonemes, since they appear only in loanwords. However, these borrowings being relatively common, they are nowadays considered part of the educated norm. The failure to use them correctly is often ridiculed in the media, e.g. if a news reporter or a high official consistently and publicly realises Belgia ('Belgium') as Pelkia. Even many educated speakers, however, still make no distinction between voiced and voiceless plosives in regular speech if there is no fear of confusion. Minimal pairs do exist: /bussi/ 'a bus' vs. /pussi/ 'a bag', /ɡorillɑ/ 'a gorilla' vs. /korillɑ/ 'on a basket'.

The status of /d/ is somewhat different from /b/ and /ɡ/, since it also appears in native Finnish words, as a regular 'weak' correspondence of the voiceless /t/ (see Consonant gradation below). Historically, this sound was a fricative, [ð], varyingly spelled as d or dh in Old Literary Finnish. Its realization as a plosive originated as a spelling pronunciation, in part because when mass elementary education was instituted in Finland, the spelling d in Finnish texts was mispronounced as a plosive, under the influence of how Swedish speakers would pronounce this letter.[15] (In the close to seven centuries during which Finland was under first Swedish, then Russian rule, Swedish speakers dominated the government and economy.) Initially, few native speakers of Finnish acquired the foreign plosive realisation of the native phoneme. As for loanwords, /d/ was often assimilated to /t/. Even well into the 20th century it was not entirely exceptional to hear loanwords like deodorantti ('a deodorant') pronounced as teotorantti, while native Finnish words with a /d/ were pronounced in the usual dialectal way. Due to diffusion of the standard language through mass media and basic education, and due to the dialectal prestige of the capital area, the plosive [d] can now be heard in all parts of the country, at least in loanwords and in formal speech.

Consonant gradation is the term used for a set of alternations which pervade the language, between a "strong grade" and a "weak grade". These alternations are conditioned by both phonology and morphosyntax and have a historical source. Historically, the phonological factor which triggered the weak grade on a given was the occurrence of a coda consonant within the same syllable. However, due to other processes of language change, there are now contexts where weak grade fails to occur in a closed syllable (Turkuun /tur.kuːn/ < /tur.kuen/ < /tur.ku.hen/), and there are contexts where the weak grade occurs in an open syllable. Morphosyntactically, the weak grade occurs in nominals (nouns, pronouns, adjectives) usually only before case suffixes, and in verbs usually only before person agreement suffixes.

The following is a general list of strong–weak correspondences.

Strong	Weak
/pː tː kː/	/p t k/
/p t/	/ʋ d/
/k/	/∅~j~ʋ/
/mp nt ŋk/	/mː nː ŋː/
/lt rt/	/lː rː/

Many of the remaining "irregular" patterns of Finnish noun and verb inflection are explained by a change of a historical *ti to /si/. The change from *ti to /si/, a type of assibilation, is unconnected to consonant gradation, and dates back as early as Proto-Finnic. In modern Finnish the alternation is not productive, due to new cases of the sequence /ti/ having been introduced by later sound changes and loanwords, and assibilation therefore occurs only in certain morphologically defined positions.

Words having this particular alternation are still subject to consonant gradation in forms that lack assibilation. Thus Finnish nouns of this type could be seen as having up to five distinct stems:[16] a word such as vesi 'water (sg. nom.)' has the forms veden (sg. gen.), vettä (sg. part.), veteen (sg. ill.) vesiä (pl. part.); as can be seen from the examples the change from t to s has only occurred in front of i. When a vowel other than i occurs, words like vesi inflect just like other nouns with a single t alternating with the consonant gradated d. Alternatively, Kiparsky proposes that all Finnish stems must end in a vowel, which in the case of polysyllabic stems may then be deleted when adding certain affixes and certain other conditions are fulfilled. For vesi he proposes the stem /vete/ (with stem final -e), which when combined with the partitive singular affix -tä/-ta drops the -e to become vet-tä (sg. part.)[17].

This pattern has, however, been reverted in some cases. Variation appears in particular in past tense verb forms, e.g. kieltää, kielsi ('to deny', 'denied') but säätää, sääti ('to adjust', 'adjusted'). Both alternate forms (kielti and sääsi) can also be found in dialects. Apparently this was caused by word pairs such as noutaa, nouti ('bring') and nousta, nousi ('rise'), which were felt important enough to keep them contrastive.

Assibilation occurred prior to the change of the original consonants cluster *kt to /ht/, which can be seen in the inflection of the numerals yksi, kaksi and yhden, kahden.

In many recent loanwords, there is vacillation between representing an original voiceless consonant as single or geminate: this is the case for example kalsium (~ kalssium) and kantarelli (~ kanttarelli). The orthography generally favors the single form, if it exists. (More completely assimilated loans such as farssi, minuutti, ooppera generally have settled on geminates.)

Consonant phonotactics are as follows.[18]

Word-final consonants

• Only /t, s, n, r, l/.
• Glottal stop [ʔ] occurs almost exclusively at word boundaries, replacing what used to be word-final consonants /k/ and /h/.

Word-initial consonants

• All consonants may occur word initially, except /d/ and /ŋ/ (although an initial /d/ may be found in loan words).

Word-initial consonant clusters

• No consonant clusters in native words, various consonant clusters in modern loanwords (e.g. /klinikkɑ/ = 'clinic', /psykoloɡiɑ/ = 'psychology', /stɑtistiikkɑ/ = 'statistics', , /strɑteɡiɑ/ = 'strategy').

Word-final consonant clusters

• None, except in dialects via vowel dropping.

Word-medial consonant clusters

• The following clusters are not possible:
  • any exceeding 3 consonants (except in loan words)
  • stop + nasal
  • labial stop + non-labial stop
  • non-dental stop + semivowel
  • nasal + non-homorganic obstruent (except /nh/)
  • nasal + sonorant
  • liquid + liquid
  • semivowel + consonant

Vowel phonotactics are as follows.[19]

Word-final and word-initial vowels

• Any of the vowels can be found in this position.

Vowel sequences

• Doubled vowels
  • Usually only the vowels /ɑ, æ, i, y, u/ are doubled.
  • Sometimes the mid vowels /e, o, ø/ can be doubled in cases of contraction.
• Diphthongs
  • Of the 18 diphthongs, 15 are formed from any vowel followed by a close vowel. The 3 exceptions are /uo, yø, ie/.
• Vowel combinations
  • Approximately 20 combinations, always at syllable boundaries.
  • Unlike diphthongs, the second vowel is longer, as is expected, and it can be open /ɑ/ or /æ/.
  • Sometimes 3–4 vowels can occur in a sequence if a medial consonant has disappeared.

Stress in Finnish is non-phonemic. Like Hungarian and Icelandic, Finnish primary stress always occurs on the first syllable of a word.[20] Secondary stress normally falls on odd-numbered syllables. Contrary to primary stress, Finnish secondary stress is quantity sensitive. Thus, if secondary stress would normally fall on a light (CV.) syllable but this is followed by a heavy syllable (CVV. or CVC.), the secondary stress moves one syllable further ("to the right") and the preceding foot (syllable group) therefore contains three syllables. Thus, omenanani ("as my apple") contains light syllables only and has primary stress on the first syllable and secondary on the third, as expected: ómenànani. On the other hand, omenanamme ('as our apple') has a light third syllable (na) and a heavy fourth syllable (nam), so secondary stress falls on the fourth syllable: ómenanàmme.

Certain Finnish dialects also have quantity-sensitive main stress pattern, but instead of moving the initial stress, they geminate the consonant, so that e.g. light-heavy CV.CVV becomes heavy-heavy CVCCVV, e.g. the partitive form of "fish" is pronounced kalaa in the quantity-insensitive dialects but kallaa in the quantity-sensitive ones (cf. also the examples under the "Length" section).

Secondary stress falls on the first syllable of non-initial parts of compounds, for example the compound puunaama, meaning "wooden face" (from puu, 'tree' and naama, 'face'), is pronounced [ˈpuːˌnɑː.mɑ] but puunaama, meaning "which was cleaned" (preceded by an agent in the genitive, "by someone"), is pronounced [ˈpuː.nɑː.mɑ].

Finnish is not really isochronic at any level. For example, huutelu ('shouting') and huuhtelu ('flushing') are distinct words, where the initial syllables huu- and huuh- are of different length. Additionally, acoustic measurements show that the first syllable of a word is longer in duration than other syllables, in addition to its phonological doubling.