Knowledge of the Finnish language is very useful

When you live in Finland, it is worthwhile studying Finnish. You will benefit a lot from understanding Finnish.
When you understand Finnish, it will be easier for you to attend to your affairs, get to know people, make friends and keep abreast of the news. You will also need to know Finnish for most jobs. If you want to study in Finland, you will probably need Finnish language skills. If you want to apply for Finnish citizenship, you must be able to speak Finnish (or Swedish or the Finnish sign language).
The best way to learn the language is to speak it.
Source: InfoFinland
In Hämeenlinna, you can study Finnish on courses arranged by Häme TE Office, Vanajavesi Adult Education Centre, language clubs of the Hämeen Setlementti Association or independently.