The "-free" Suffix (-ton / -tön)
To describe something as being without a specific ingredient or quality—like "gluten-free" or "meatless"—Finnish uses the suffix -ton or -tön. Vowel harmony dictates the form: use -ton if the word contains back vowels (a, o, u), and -tön otherwise.
When discussing mass nouns (uncountable foods and liquids) or negative sentences, you will frequently need the partitive case. Adjectives ending in -ton or -tön become -tonta or -töntä in the partitive.
Word Stems and Consonant Gradation
The suffix attaches to a word's inflected stem (the same stem used for the genitive). If the noun undergoes consonant gradation, it uses its "weak" form.
For instance, the t in maito (milk) softens to a d in the stem maido-, giving us maidoton.
Whether you are grocery shopping or checking a menu, these forms follow a highly predictable pattern:
Vowel harmony rules apply identically to the partitive endings, as seen with the front vowels in pähkinä (nut):
Beyond Food
This suffix also works for abstract concepts and lifestyle choices. For example, tarve means "a need," making tarpeeton "unnecessary" or "needless."