Learn Hardcore Finnish: Valmentaja näytti meille taukojumpan, joka parantaa ergonomiaa konttorilla. - The coach showed us a stretch break that improves ergonomics at the office.

In the sentence you see taukojumpan. That is the genitive singular form of taukojumppa, used here as the object of the verb näytti:

taukojumppa (dictionary form, nominative)
taukojumpan (genitive, used here as a total object)

A natural English translation is a (short) break exercise / desk exercise.

Why is taukojumpan in the form with -n, not taukojumppaa?

Taukojumpan is the genitive singular, used as a total object in Finnish.

For many verbs, especially in past tense, you have a choice between:

total object (genitive or nominative): the action is seen as complete, affecting the whole thing
partial object (partitive): the action is incomplete, ongoing, or affects only part of something

Compare:

Valmentaja näytti meille taukojumpan.
→ The coach showed us the whole exercise / a specific exercise (complete unit).
Valmentaja näytti meille taukojumppaa.
→ The coach showed us some (of the) break exercise, or showed it partly / for a while. This sounds odd here unless you are emphasizing “showed it a bit”.

Because the coach is presenting a specific complete exercise routine, taukojumpan (total object) is natural.

What does Valmentaja mean, and is it only for sports coaches?

Valmentaja is a noun meaning coach or trainer.

In sports: a coach of a team or an athlete.
In other contexts: a trainer, instructor, or even a kind of workplace wellbeing coach, which fits this sentence well.

It does not mark gender; Finnish nouns are gender-neutral. Context tells you whether this is a sports coach, a corporate trainer, a personal trainer at the gym, etc.

Why is the verb näytti used instead of näyttää?

Näyttää is the basic (dictionary) form, meaning to show.

näyttää = to show (present tense stem: näytä-)
näytti = showed (past tense, 3rd person singular)

In Finnish, one way to form the past tense is:

take the stem (näytä-)
change it to the past stem (näytt-)
add past tense ending (-i) and person ending
→ näytti = he/she showed

So Valmentaja näytti = The coach showed (in the past).

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

Meille is the allative form of me (we).

Basic forms of me:

me = we (nominative)
meitä = us (partitive)
meidät = us (accusative, total object)
meille = to us (allative)

The verb näyttää (to show) typically uses the pattern:

show something (object) to someone (allative)
näyttää jotakin jollekin

So:

taukojumpan = the thing being shown (object)
meille = to us (indirect object; the recipients)

Literal structure: The coach showed to us the break exercise.

English usually says showed us the exercise, but Finnish grammar marks “to us” explicitly with -lle (meille).

How does the relative pronoun joka work here, and why not mikä?

Joka is a relative pronoun meaning roughly which / that / who. It refers back to a specific noun mentioned before.

In the sentence:

Antecedent: taukojumpan (the break exercise)
Relative pronoun: joka
Clause: joka parantaa ergonomiaa konttorilla

So joka = which / that, referring to the break exercise.

Why not mikä?

Joka is used when the antecedent is a normal noun: taukojumppa, kirja, ihminen, etc.
Mikä is used mainly when the antecedent is:
- a whole preceding sentence or idea
  - Hän myöhästyi, mikä oli ikävää. → He was late, which was annoying.
- a superlative (paras, suurin) or some pronouns/determiners (se, kaikki, etc.)

Since the relative clause clearly describes taukojumpan, a concrete noun, joka is the correct choice.

What is the role of joka inside its clause?

Inside the clause joka parantaa ergonomiaa konttorilla, joka is the subject.

joka (subject)
parantaa (verb)
ergonomiaa (object)
konttorilla (adverbial of place)

So the structure is: (The exercise) improves ergonomics at the office.

Because joka is the subject, it appears in the nominative form (not inflected for any other case in this sentence).

Why is ergonomiaa in the partitive case, not ergonomian?

Ergonomiaa is the partitive singular of ergonomia (ergonomics).

Many verbs that mean improving, increasing, doing something to an abstract quality often take the object in the partitive, especially when:

you cannot easily think of the thing as a bounded, complete object
or the action is about increasing or changing the degree of something

With parantaa (to improve, to cure), there is a subtle pattern:

parantaa haavan → cure the wound (a concrete, fully curable object)
parantaa taloutta / ergonomiaa → improve the economy / ergonomics (an ongoing, degree-like quality) → partitive

So parantaa ergonomiaa expresses improving ergonomics (some amount / degree) rather than completely fixing one specific ergonomics-thing. Using ergonomian would sound unusual here.

What does konttorilla mean, and how is it different from konttorissa?

The base noun is konttori = office.

Two common location cases:

konttorissa (inessive, -ssa / -ssä) = in(side) the office
konttorilla (adessive, -lla / -llä) = roughly at the office, at the workplace (more general)

In practice:

konttorissa emphasizes being inside the physical room / building.
konttorilla often means at one’s office job / at the office as a workplace, not focusing on being physically inside four walls.

In this sentence, ergonomiaa konttorilla is about office ergonomics at the office as a workplace, so konttorilla (adessive) is natural.

Why is there a comma before joka in Finnish?

Finnish punctuation rules are stricter about commas between main clauses and subordinate clauses than English.

Any subordinate clause, including a relative clause introduced by joka, is normally separated by a comma from the main clause.

So:

Valmentaja näytti meille taukojumpan, joka parantaa ergonomiaa konttorilla.

The comma marks the boundary between:

main clause: Valmentaja näytti meille taukojumpan
relative clause: joka parantaa ergonomiaa konttorilla

Even if in English you might sometimes omit the comma before that, Finnish keeps it here.

Can the word order Valmentaja näytti meille taukojumpan be changed?

Yes, Finnish word order is fairly flexible. Some possible variants:

Valmentaja näytti meille taukojumpan.
Neutral, subject–verb–indirect object–direct object.
Valmentaja näytti taukojumpan meille.
Almost the same meaning; slight emphasis can fall on meille at the end.
Meille valmentaja näytti taukojumpan.
Emphasis on meille: “It was to us that the coach showed the break exercise (maybe not to others).”

The grammatical roles stay clear because of case endings:

Valmentaja (subject, nominative)
meille (allative, to us)
taukojumpan (object, genitive)

Changing the order mainly affects emphasis / information structure, not basic meaning.

What would be a fairly literal English rendering of the whole sentence, and how does it differ from natural English?

A fairly literal rendering is:

The coach showed to us the break exercise, which improves ergonomics at the office.

More natural English might be:

The coach showed us a break exercise that improves ergonomics at the office.

Differences:

Finnish explicitly marks “to us” with meille; English usually just says showed us.
Finnish has no articles, so taukojumpan can be a break exercise or the break exercise, depending on context.
The Finnish relative pronoun joka can correspond to English which or that.
konttorilla is closer to at the office than in the office.