Learn Hardcore Finnish: Kun kokki hymyilee, koko leipomo tuoksuu vielä paremmalta. - When the chef smiles, the whole bakery smells even better.

Kun is a conjunction meaning “when,” used to introduce a temporal (time) clause. It tells us when something happens. It is not the same as kuin, which is used for comparisons (“than”) or to introduce clauses like “as” in English.

Why is there a comma right after hymyilee?

In Finnish, a subordinate clause (here the Kun-clause) is separated from the main clause by a comma. Since the Kun-clause comes first, you place a comma before the main clause.

What does koko leipomo mean, and is koko here the same word as “size”?

Here, koko is an adjective meaning “whole” or “entire,” modifying leipomo (“bakery”). It is spelled the same as the noun koko (“size”), but in this sentence it’s not “size” at all—it simply intensifies: “the whole bakery.”

What case are kokki and koko leipomo, and why?

Both kokki and koko leipomo are in the nominative case. They are the subjects of their respective clauses:

kokki (the cook) smiles
koko leipomo (the whole bakery) smells

What does tuoksuu mean, and what is its infinitive form?

tuoksuu is the 3rd person singular present form of tuoksua, which means “to smell” (in the sense of “give off a smell” or “smell good”). The base form is tuoksua.

How is paremmalta formed? Why is it in the ablative case (-lta)?

paremmalta breaks down into:

parempi (comparative of hyvä “good” → “better”)
-lta (ablative case ending)

With sensory verbs like tuoksua (“to smell [good]”) or maistua (“to taste [good]”), the perceived quality goes into the ablative case, literally “from how it smells/tastes.” Hence paremmalta = “(from) better.”

Why is vielä used here? What nuance does it add?

vielä literally means “still,” but in comparative constructions it often carries the sense “even.” So vielä paremmalta = “even better (in terms of smell).”

Could we use jos instead of kun? What difference would that make?

jos means “if” and introduces a conditional idea (“if the cook smiles”). Kun implies a real or habitual action (“when the cook smiles”). Swapping kun for jos would change the nuance to “if by chance the cook smiles,” rather than the more definite or recurring “when.”

Is the word order in this sentence fixed? Could we move tuoksuu earlier?

Finnish word order is relatively flexible, but neutral main-clause order is S (subject)–V (verb)–A (adverbial), as in koko leipomo tuoksuu vielä paremmalta. You could move elements for emphasis, but doing that in everyday language sounds marked. Also, if you put the main clause first, you could write: “Koko leipomo tuoksuu vielä paremmalta, kun kokki hymyilee.”
In that case, the comma before the Kun-clause is optional.