After 'yksi' (one) the noun is in its plain dictionary form, but after two or more the noun goes into the partitive singular - never the plural. The partitive usually adds -a/-ä, -ta/-tä to the word.
Examples
- Yksi olut, kiitos.
- One beer, please.
- Kaksi kahvia, kiitos.
- Two coffees, please.
- Minulla on neljä kirjaa.
- I have four books.
- Odota viisi minuuttia.
- Wait five minutes.
The mistake to avoid
Learners make the noun plural after a number ('kaksi kahvit') - it must stay singular partitive: kaksi kahvia.
Where this fits in
Numbers, days, time, Finnish A1: Count, talk about days and months, give the time, and handle numbers in real situations.