Collective Nouns with -sto / -stö
To create a noun that describes a collection, group, or system of something, Finnish uses the suffix -sto or -stö. Just like with other suffixes, remember to follow vowel harmony: use -stö if the word has front vowels (y, ä, ö), and -sto otherwise.
- laiva (ship) → laivasto (navy / fleet)
- saari (island) → saaristo (archipelago)
- puu (tree) → puusto (stand of trees)
| Finland's navy is small but efficient. | Suomen laivasto on pieni mutta tehokas. |
| There is a lot of tree cover in the archipelago. | Saaristossa on paljon puustoa. |
Systems and Equipment
This suffix is extremely useful for grouping individual mechanical parts or tools into a unified system or set.
- laite (device) → laitteisto (equipment / hardware)
- kone (machine) → koneisto (machinery)
| The new equipment is in the factory. | Uusi laitteisto on tehtaassa. |
| This machinery is too old. | Tämä koneisto on liian vanha. |
People, Institutions, and Concepts
You will frequently see -sto / -stö used to describe groups of people, abstract collections, and administrative bodies. Note that the root word's stem may undergo consonant gradation or slight changes when the suffix is attached.
- henkilö (person) → henkilöstö (personnel / staff)
- väki (people) → väestö (population)
- raha (money) → rahasto (fund)
- sääntö (rule) → säännöstö (set of rules)
- lehti (newspaper) → lehdistö (the press)
| The whole staff is on sick leave today. | Koko henkilöstö on tänään sairauslomalla. |
| The country's population is large. | Maan väestö on suuri. |
Because these new words are standard nouns, they inflect normally. You can add all the usual location cases to them, such as the illative (-Vn) to move into a collection, or the elative (-sta / -stä) to say from or about it.
| If you have money, invest it in the fund. | Jos sinulla on rahaa, sijoita se rahastoon. |
| The press writes about this new set of rules. | Lehdistö kirjoittaa tästä uudesta säännöstöstä. |