When you are learning a language as hard as Finnish is, and concurrently you are living in Finland, your language needs outpace your language ability for a long time. This means you're constantly improvising and saying things that you don't really know how to say, without the capacity to realize it or fix it.
Then you have the singular joy of sitting in Finnish class and finding out that you've been saying x wrong for a year and a half, x being a thing that you needed to say that one time, so you battled through it and did your best and then stuck with it since then. But you were wrong. You don't say x like that. You say it this other way.
I have these revelations in Finnish class all the time now - it's like they saved all the really useful stuff for the third course/book two of the textbook series. Fact: Suomen Mestari does not teach you past tense until book two. If someone asks you about your weekend, you cannot answer a thing (beyond "oh, nothing much") until you've finished all of book one and have started book two. So past tense was a major chunk of my "I've been saying this wrong" a-ha moments. (To be fair, every once in a while, I find out I've been saying something right, too.)
This week's embarrassing discoveries: tarvita and kuume. Tarvita means 'to need,' and so as soon as I could conjugate it, I used it to say, you know, "I need chocolate" but also "I need to buy a ticket" or whatever. But it turns out (as I learned last week) that you can't use tarvita with verbs, only with nouns. There's a whole other way to say "I need to verb." So I was doing that wrong.
Kuume means fever. So whenever Sterling has had a fever, I've told päiväkoti that he can't come because hänella on kuume. I've suspected for a while that I was doing it wrong, because his teachers always seemed to miss a beat before they understood. And today I learned that you have to put kuume into the partitive case - he's got a bit of a fever, not the whole thing. So it's hänella on kuumetta.
(I also learned that nuha is not, as Jeremy and I were puzzling over last week, someone's name. Sterling's teachers kept talking about nuha. It means he has the sniffles. There is not a little girl named Nuha.)
On the one hand, it's embarrassing to know I've been saying things wrong. But on the other hand, it feels good to learn the right way to say something - like cleaning house and tidying up my Finnish!