Tarvitsen verokortin seuraavaa työvuoroa varten, jotta palkka maksetaan oikein.

Tarvitsen is the verb tarvita (to need) in the present tense, 1st person singular:

• minä tarvitsen = I need Other forms for comparison:
• sinä tarvitset = you need
• hän tarvitsee = he/she needs
• me tarvitsemme = we need

Verokortin is the object in the total object form (often called accusative, but it looks like the genitive -n in singular nouns).

• verokortti (basic form) → verokortin Using the total object suggests you mean a specific, complete thing: you need (the/a) tax card (not “some tax card” or “part of it”).

Verokorttia would be the partitive object, which often implies:

• an unspecific or partial need, or
• an ongoing / not completed situation.

So:

• Tarvitsen verokortin = I need the tax card (a complete, concrete item; typical here)
• Tarvitsen verokorttia = I need (some) tax-card-related thing / I’m in need of a tax card (less natural in this specific context)

The postposition varten (for; for the purpose of) typically governs the partitive:

• tätä varten = for this (purpose)
• seuraavaa työvuoroa varten = for the next shift

So both words agree in the partitive singular:

• seuraava → seuraavaa
• työvuoro → työvuoroa

Varten is a postposition (like a preposition, but it comes after its noun phrase). It forms a phrase meaning for / for the purpose of:

• seuraavaa työvuoroa varten = for the next work shift

Word order is typically:

• noun phrase + varten

Because jotta introduces a subordinate clause (a purpose/result clause). In Finnish, a subordinate clause is normally separated with a comma:

• main clause: Tarvitsen verokortin seuraavaa työvuoroa varten,
• subordinate clause: jotta palkka maksetaan oikein.

Jotta typically expresses purpose (so that / in order that):

• … jotta palkka maksetaan oikein = … so that the pay is paid correctly

Että is more neutral and often corresponds to that (reporting content), not purpose:

• Hän sanoi, että… = He said that…

Maksetaan is the passive present of maksaa (to pay). Finnish passive is often used when:

• the doer is unknown, obvious, or not important (e.g., the employer/payroll system)
• you want an impersonal tone

So palkka maksetaan oikein is like the pay will be paid correctly / they will pay the pay correctly (without naming who “they” are).

In Finnish passive, the thing being paid is commonly in the nominative when it’s a “whole/total” item:

• Palkka maksetaan = The pay is paid (in full / as a complete amount)

If you used the partitive (palkkaa), it would suggest something like an incomplete/ongoing amount or a less bounded idea:

• palkkaa maksetaan can sound like (some) pay is being paid / pay is being paid (in general)

Yes. Finnish present tense often covers near future or scheduled events, especially with context:

• palkka maksetaan oikein can naturally mean the pay is/will be paid correctly (e.g., on the next payday)

Oikein is an adverb meaning correctly in this context:

• maksaa oikein = to pay correctly

Oikeasti usually means really / genuinely / actually, not “correctly”:

• Oikeasti? = Really? So here oikein is the natural choice for correctly.

That would be unnatural/incorrect in standard Finnish, because että doesn’t normally introduce a purpose clause. For purpose, you use:

• jotta (most common)
• sometimes että can appear in certain colloquial or fixed patterns, but in this sentence jotta is the correct, idiomatic option.