Questions & Answers about Se on yleinen tapa Suomessa.
In this sentence, se means “it/that” and refers back to something already known from context (for example, some behavior you just mentioned).
- se = it / that (neutral 3rd person pronoun, very common)
- tämä = this (physically or mentally “close”; often a bit more “pointing at it”)
- hän = he / she (used for people in more formal/neutral style)
In everyday spoken Finnish, people often use se even for people (“it/he/she”), but in standard written Finnish you normally use:
- hän for people
- se for things, ideas, facts, situations
So here se is “it/that (thing we are talking about) is a common habit in Finland.”
on is the 3rd person singular present tense form of the verb olla (“to be”).
- olla = to be (dictionary form)
- minä olen = I am
- sinä olet = you are (singular)
- hän / se on = he / she / it is
- me olemme = we are
- te olette = you are (plural / formal)
- he ovat = they are
So se on literally means “it is / that is”. Finnish doesn’t use an extra helper verb like English “do”; you just conjugate olla itself.