Päivää ! So I am a student in finnish language in Paris. Unfortunately there is no book about finnish grammary. Even if you get it in english I would it. Then…

The Finnish grammar is available in the internet. On the following sites you’ll find it both in
English and in French:

http://www.uta.fi/~km56049/finnish/
http://www.cc.jyu.fi/~pamakine/kieli/suomi/
http://fr.wikipedia.org/wiki/Finnois

The following titles offer you the Finnish grammar in book form, one of them in French.

- Fred Karlsson: Finnish- an essential grammar, Routledge 1999, ISBN 0415207045
- Merja Karjalainen and Helena Sulkala: Finnish, Routledge 1992, ISBN 0415026431
- Limnell, Eija: Finnois express (Finlande) : guide de conversation, les premiers mots utiles, notions de grammaire, culture et civilisation, renseignements pratiques, Editions du Dauphin 2006
ISBN 2-7163-1323-7