One day, I asked my Finnish teacher if it was true that her language had 30 different words for snow. She fixed me with her big, blinky eyes.

“No, you poor deluded fool,” she sighed. “We Finns only have one word for ‘snow’. The trouble is, you English think that everything white that falls out of the sky is ‘snow’.”

Finnish actually has more than thirty words for frozen precipitation in a variety of forms, including a word for “powdery snow that’s melted just a little bit” (nuoska), a “thin bit of snow on top of ice” (iljanne), and even “the grey lumpy stuff that turns up when slush refreezes” (kohva). Finns have a similarly large number of words for “reindeer”, and an oddly precise verbal toolkit for describing cupboards. However, their language doesn’t distinguish between sponges and mushrooms, and a single vowel sound separates the differing semantics of “My shelves are nearly full” from “My madness is soon to end.”

Of course, there is nothing “special” about Finnish. Every language has its little peculiarities, evolved in reaction to particular situations. The Navajo don’t distinguish between pilots, insects or helicopters, while the Chinese have over a dozen shades of red. And Japanese has 1194 ways to say “I love you”, along with a culture that refuses to use any of them. Having studied many languages and mastered none, I always return with joyous appreciation to English because it is such a catastrophic car-crash of Latin, Anglo-Saxon, Norman French and Viking Danish, with grammar rules deriving from several different countries, and a veritable multicultural bar-fight of contending nuances, much of which comes down not only to class, but to what someone’s great-great-great grandfather did for a living.

In his novel New Finnish Grammar, Diego Marani latches upon Finnish as a test subject for the human condition. In 1940s Italy, an expat Finnish doctor finds a patient with amnesia so severe that he cannot even remember how to speak. Finding evidence on the man’s person that he is a Finn, the doctor begins to teach him Finnish from scratch. As Sapir and Whorf once argued with their Linguistic Relativity Hypothesis, the language in which one thinks affects the thoughts that one can have. What if this man isn’t Finnish at all? What will this re-programming do to him?

And if he isn’t a Finn called Sampo Karjalainen, who is he? And who will he be when his brain is wired with thirty words for white stuff that falls out of the sky? There are numerous precedents in fiction, most notably the Kaurismäki film Man Without A Past, and many science fiction novels that deal with the power of language to shape thought. But Marani, a professional linguist, latches onto Finland and Finnishness itself for an extended meditation on human nature, patriotism and the soul.

Finnish has vowel harmonies and consonantal mutations like Turkish, and a cavalcade of odd little cases that make it infuriatingly precise. Most languages have basic items like singular and plural, nominative and genitive. Finnish has its own bonkers additions, like the abessive, which is the case you use for things that are nothing to do with you, and the partitive, which is a sort of superglue case to fix all the others.

Marani’s book returns to the age old tug-of-war between nature and nurture. Is Finnish the way it is because of Finland, or are Finns the way they are because of Finnish? He delves into the Kalevala, that crazy national myth of mighty duels over a sci-fi McGuffin, itself was knocked up as an exercise in bootstrap nationalism in the 19th century. He points to the savage rending of Finland into Reds and Whites during the Russian Revolution, an apocalyptic shattering of social cohesion that is still largely unspoken-of today, and yet which, only recently, I have still seen erupt into a bar-room brawl around me.

Talking to a Finnish history teacher this year, I heard the tale of her grandmother’s funeral, to which only a single cousin came. The reason: sixty years ago, grandma married someone of “the wrong colour”. Tellingly, I was not told which colour, Red or White, was wrong. It only mattered that the twain could never meet.

And, of course, there is Mannerheim, that national demigod – a former spy and orientalist, catapulted out of a dead-end military career into a role as the country’s leader in the unwinnable Winter War. Mannerheim, too, was a reluctant student of Finnish, living for most of his life with only a smattering sufficient to deal with the servants. It was only in middle age, called upon to deliver speeches to his public, that he swotted up sufficiently. Extant speeches show his Finnish to be halting and strangely accented – a sign that this hero of “Finnish” nationalism was a native speaker of Swedish, who had spent 30 years in the Russian army.

Marani is a good linguist, with a fine ability to romanticise issues that most people would find dull. He describes the construction of a Finnish sentence with allusions to orbits and trajectories in an imaginary solar system. He delves into the etymology of the simplest words with a verve that conjures wizards in primeval forests and witches chanting spells over swamps. He also writes himself a get-out-of-jail-free card, using his narrator’s student status as an excuse for numerous typographical and grammatical errors – annoyingly, even in a book that sings of the joys of vowel harmony, there are misplaced umlauts and errant letters.

One day, New Finnish Grammar is going to be a great movie. Some worthy agglutination of government funding bodies will knock up a Europudding that shoots in Trieste and Helsinki, starring a great Finnish actor like Mikko Kouki as the amnesiac Sampo. There is just enough plot in Marani’s narrative to sustain a movie, with cutaways to the essence of Finnishness, and fight scenes on the Eastern front against the Russians, perhaps even with magic-realist scenes that illustrate the wonder of Finnish grammar with Marani’s warlocks and witches, paintings of Akseli Gallen-Kallela come to life, or symbolic representations of what happens when a subject switches from accusative to partitive.

Well, maybe not the last. Three years into my Finnish lessons at the London School of Slavonic and East European Studies, mere weeks away from attaining my Lower Intermediate diploma, my teacher coughed nervously, and told the class to prepare themselves for a Finnish bombshell.

“The thing is,” she said, “Finnish doesn’t really have an accusative case. Don’t panic, we can use the genitive or partitive just fine, but everything I have told you so far about the accusative has been a convenient lie.”

She patted the arm of one of my fellow classmates, who had started to sob.

“Don’t cry,” she said. “It’ll be all right. It’ll be all right.”

Jonathan Clements is the author of An Armchair Traveller’s History of Finland.