Learn Hardcore Finnish: Talvella lumi peittää kadun kokonaan, ja myrsky tekee kävelystä vaikeaa. - In winter the snow covers the street completely, and the storm makes walking difficult.

talvella = adessive case (talvi
- -lla)
- Often used for time expressions: kesällä (in summer), talvella (in winter), päivällä (in the daytime), yöllä (at night).
- Roughly “at/during winter”.
talvessa = inessive case (talvi
- -ssa)
- Literally “inside winter” and would normally sound odd as a time adverbial.
- It might appear in very specific, poetic, or metaphorical contexts, but not as the neutral way to say “in winter”.

So, when you talk about the season as a time period, Finnish almost always uses talvella, not talvessa.

What case is kadun, and why is it used here?

Kadun is the genitive singular form of katu (“street”). In this sentence it functions as a total object, which in Finnish very often appears in the -n (genitive-looking) form.

Dictionary form: katu (“street”)
Genitive/total object: kadun

With verbs like peittää (“to cover”), you choose the object case based on how complete the action is:

Lumi peittää kadun (kokonaan).
“The snow covers the (whole) street.” – total object (kadun) because the street ends up fully covered.
Lumi peittää katua.
“The snow is covering (some of) the street.” – partitive object (katua) for an ongoing or partial action.

Here, kadun + kokonaan clearly presents the street as completely covered, so Finnish uses the total object form kadun.

What does kokonaan add, and how is it different from koko kadun?

Both express the idea of “completely”, but they work a bit differently:

kokonaan is an adverb: “completely, entirely, altogether”.
- Lumi peittää kadun kokonaan.
  “The snow covers the street completely.”
  → Focus is on the result of the action being complete.
koko is an adjective/determiner meaning “whole, entire”.
- Lumi peittää koko kadun.
  “The snow covers the entire street.”
  → Focus is on every part of the street being involved.

In practice, kadun kokonaan and koko kadun would usually be interchangeable here, but:

koko kadun emphasizes that all of the street is affected,
kadun kokonaan emphasizes that the covering is complete.

Can the word order in Talvella lumi peittää kadun kokonaan be changed?

Yes. Finnish has relatively flexible word order. Different orders are possible and usually correct, but they change emphasis:

Talvella lumi peittää kadun kokonaan.
Neutral English rendering: “In winter, snow completely covers the street.”
→ Talvella (time) is the starting point; we’re talking about what happens in winter.
Lumi peittää kadun kokonaan talvella.
→ More neutral “Snow covers the street completely in winter”; the time is less emphasized.
Kadun lumi peittää kokonaan talvella.
→ Emphasizes kadun: “It’s the street that the snow completely covers in winter” (somewhat marked in tone).

Fronting Talvella is a very common way to introduce a general, habitual situation tied to a season. It’s natural and idiomatic.

Why is there a comma before ja in ..., ja myrsky tekee kävelystä vaikeaa?

Finnish comma rules differ from English, but here the comma is standard.

We have two independent main clauses:
1. Talvella lumi peittää kadun kokonaan
2. myrsky tekee kävelystä vaikeaa
They are joined by ja (“and”), and each has its own subject:
- 1st subject: lumi
- 2nd subject: myrsky

In Finnish, when ja connects two main clauses with different subjects, a comma is normally placed before ja:

Lumi peittää kadun, ja myrsky tekee kävelystä vaikeaa.

If the subject were the same and not repeated, there would usually be no comma:

Lumi peittää kadun ja tekee kävelystä vaikeaa.
(One subject, lumi, doing both actions.)

What exactly is going on grammatically in myrsky tekee kävelystä vaikeaa?

The structure is:

myrsky – subject (“storm”)
tekee – 3rd person singular of tehdä (“to make, to do”)
kävelystä – elative singular of kävely (“walking”)
vaikeaa – partitive singular of vaikea (“difficult”)

Pattern:

tehdä + (jostakin) + (joksikin / joksikinlaista)
“to make (something) (into something / in some state)”

In this specific idiomatic pattern:

tehdä jostakin vaikeaa / helppoa / mahdotonta
“to make something difficult / easy / impossible”

So myrsky tekee kävelystä vaikeaa literally:
“the storm makes (from) walking difficult” → “the storm makes walking difficult.”

Here:

kävelystä marks the thing affected (the activity of walking),
vaikeaa is the resulting quality in partitive.

Why is kävelystä in the -stä form and not just kävely or kävelyä?

Kävelystä is the elative case of kävely (“walking”):

Dictionary form: kävely
Elative: kävelystä (“from walking / out of walking”)

With tehdä in this “make X (adjective)” meaning, Finnish commonly uses the pattern:

tehdä jostakin + adj(partitive)
literally: “make from something [adj]”

Examples:

He tekevät elämästä vaikeaa.
“They make life difficult.”
Sade tekee ajamisesta vaarallista.
“Rain makes driving dangerous.”

So:

Elative (-sta/-stä) = the thing being affected / the ‘source’.
You do not say *kävelyä vaikeaa in this pattern; elative is fixed by the verb construction.

You could rephrase with a different structure:

Myrsky tekee kävelyn vaikeaksi.
(Here kävelyn is genitive and vaikeaksi is translative; slightly different pattern but similar meaning.)

Why is it vaikeaa and not vaikea or vaikeaksi?

Vaikeaa is the partitive singular of vaikea (“difficult”):

Dictionary form: vaikea
Partitive singular: vaikeaa

Why partitive?

With this pattern tehdä jostakin + adjective, Finnish normally puts the adjective in the partitive when it describes a quality rather than labeling it as a fixed, classified “thing”:

Myrsky tekee kävelystä vaikeaa.
→ “The storm makes walking difficult” (gives walking the quality of being difficult).

Contrast:

Myrsky tekee kävelystä vaikean (tehtävän).
→ More like “The storm makes walking a difficult task.”
Now vaikean (genitive) is more like a classifying adjective tied to a (often implicit) noun.

Why not translative (vaikeaksi)?

You sometimes see:

Myrsky tekee kävelyn vaikeaksi.

Here:

kävelyn = genitive,
vaikeaksi = translative (“into difficult”).

This emphasizes a change of state (“makes it become difficult”).
The original kävelystä vaikeaa is just the most common idiomatic pattern for “makes X difficult” and doesn’t focus as strongly on the change itself.

So:

kävelystä vaikeaa – very typical, quality-focused expression.
kävelyn vaikeaksi – also possible, slightly different structure and nuance.

Why does vaikeaa have a double aa at the end?

This is just how the partitive singular is formed for adjectives ending in -ea:

vaikea → stem vaikea-
- partitive ending -a → vaikeaa
pitkä (“long”) → pitkää
erikoinen (“special”) → erikoista

So, for vaikea:

The stem ends in -a, and you add -a for the partitive.
In spelling, that gives aa: vaikea + a → vaikeaa.

Phonetically it’s just a long a sound.

Could you say Myrsky tekee kävelemisestä vaikeaa instead of kävelystä vaikeaa?

You could say:

Myrsky tekee kävelemisestä vaikeaa.

Here käveleminen is the -minen verbal noun (“the act of walking”), and kävelemisestä is its elative form.

Difference in nuance:

kävelystä (from kävely)
→ More like the noun “walking” as an activity; very natural and concise here.
kävelemisestä
→ Focuses a bit more on the process of walking; often slightly more formal or explicit.

Both are grammatical and understandable. In everyday style, kävelystä vaikeaa is simpler and very idiomatic.

Why is the verb in the present tense (peittää, tekee) when the English translation talks about what happens in winter in general?

Finnish present tense covers both:

actions happening right now, and
timeless or habitual actions (things that regularly happen).

In this sentence:

Talvella lumi peittää kadun kokonaan
– “In winter, snow covers the street completely” (a recurring, typical situation).
Myrsky tekee kävelystä vaikeaa
– “A storm makes walking difficult” (whenever there is a storm).

English also uses the simple present for general truths and habits, so the tense choice lines up quite well between the languages here. There’s no special habitual tense in Finnish; the simple present handles that meaning.

What are the dictionary forms of the main words, and how are they inflected here?

Here are the key content words:

Talvella ← dictionary form talvi (“winter”)
→ talvi
- adessive -lla → talvella (“in winter / during winter”)
lumi – already in dictionary form (“snow”), nominative singular, subject.
peittää – dictionary form peittää (“to cover”), here used as 3rd person singular present; in Finnish the 3rd person singular present is identical to the infinitive form:
- hän peittää / lumi peittää.
kadun ← dictionary form katu (“street”)
→ genitive / total object kadun (“the street (as a whole)”).
kokonaan – adverb from the base koko (“whole”), meaning “completely, entirely”.
myrsky – dictionary form myrsky (“storm”), nominative singular, subject of the second clause.
tekee ← dictionary form tehdä (“to make; to do”)
→ 3rd person singular present: hän tekee, myrsky tekee.
kävelystä ← dictionary form kävely (“walking (as an activity)”)
→ elative singular kävelystä (“from/out of walking”), required by the verb tehdä in this pattern.
vaikeaa ← dictionary form vaikea (“difficult”)
→ partitive singular vaikeaa, used as a predicative adjective here: “difficult”.