Think in Finnish


A monophthong is a single vowel sound and a diphthong is a blend of two different vowel sounds within a single syllable.

Finnish has eight vowels that make up eight monophthongs, and 16 common diphthongs and two uncommon diphthongs.


Finnish monophthongs are as follows:

Vowels Finnish English
a appelsiini orange
e elokuu August
i iso big
o omena apple
u ulos out
y yksi one
ä älä do not
ö öljy oil


If two vowels are next to each other, they might or might not create a diphthong. If one vowel belongs to one syllable and the other vowel belongs to a another syllable, they are monophthongs and pronounced individually.


Finnish diphthongs are as follows:

Vowels Finnish English
ai aina always
ei ei no
ie kieli language
oi soittaa to phone, call
ui uida to swim
yi hyi yuck
äi äiti mother
öi öisin at night(s)
au Australia Australia
eu Eurooppa Europe
iu liukas slippery
ou outo strange, odd, peculiar
uo Suomi Finland
äy täysin fully, completely, entirely, totally, utterly, perfectly
öy pöytä table
ey leyhyä to waft 1
iy siistiytyä to tidy up, to clean oneself up 2


If your native language is English, pay close attention to how you pronounce uo (ou) and ie (ei).

To practice diphthongs, swap the letters of each diphthong with each other and listen to the difference between them.

Vowel harmony

Finnish vowels are categorized in three groups:

  • back (a,o,u)
  • front (ä,ö,y)
  • indifferent (i,e)

The vowels in a simple (non-compound) word are either back and/or indifferent, or front and/or indifferent.

The vowels in a compound word, which is a word that contains more than one simple word, can have a combination of back and front vowels. The boundary of vowel harmony is at the simple-word level. For example, the compound word pääasia is made up of simple words pää (main) and asia (issue, thing), and as a compound word, it contains both front, back, and indifferent vowels.

Vowel harmony is very consistent in Finnish and with a bit of practice it becomes second nature.

Back Indifferent Front
a i ä
o e ö

Vowel lengths

Finnish vowels are either short or long:

  • V
  • VV

If the length of a short (or single) vowel is V, the length of a long (or double) vowel is V * 2. For example, the letter a in the word appelsiini is pronounced /ɑ/, and the double a in aamu is pronounced /ɑː/.

Finnish sounds are either short or long. For example, the letter l in the word tuuli (wind) is pronounced /l/, and the double l in tulli (customs—at a border crossing) is pronounced /lː/. This distinction between short and long sounds is important; it can mean the difference between saying, “we meet (ta p aamme)” and “we kill (ta pp aamme)".


The distinction between short and long sounds is important; pronouncing a vowel too long or too short can change the meaning of a word completely and lead to Finnish speakers not understanding you.

  1. This diphthong is uncommon. ↩︎

  2. This diphthong is also uncommon. ↩︎

Last updated on 19 Apr 2019

© 2019 Ursula Kallio