Wczoraj bolał mnie palec, więc dziś gotuję wolniej niż zwykle.

That is a very common reaction. With boleć (to hurt / to ache), Polish often uses a structure that is closer to:

[body part] hurts [person]

So:

• palec = the finger
• bolał = hurt/ached
• mnie = me

Literally, it is something like Yesterday, a finger hurt me.

In natural English we usually say My finger hurt or My finger was hurting, but Polish often keeps the person as the object-like experiencer and the body part as the grammatical subject.

So bolał mnie palec is completely normal Polish.

Because boleć normally takes the person experiencing pain in the accusative case.

So:

• ja = I (nominative) → not correct here
• mnie = me (accusative) → correct here
• mi = to me (dative) → not what boleć usually takes

That is why you say:

• Boli mnie głowa. = My head hurts.
• Bolał mnie palec. = My finger hurt.

The pattern is worth memorizing as a whole: boli / bolał / bolała / bolało + mnie / cię / go / nas...

Because the verb agrees with palec, which is a masculine singular noun.

In the past tense, Polish verbs agree in gender and number with the subject.

Here the subject is palec, so:

• palec → masculine singular
• therefore bolał

Compare:

• Bolała mnie głowa. → głowa is feminine
• Bolało mnie kolano. → kolano is neuter
• Bolały mnie palce. → palce is plural

So the ending on bolał is not about me; it is about palec.

Because in Polish, possessive words like mój, twoja, jego are often omitted when the owner is obvious from context, especially with body parts.

So Polish prefers:

• Boli mnie głowa.
• Bolał mnie palec.

rather than:

• Boli mnie moja głowa.
• Bolał mnie mój palec.

Adding mój is possible, but it usually adds emphasis, contrast, or sounds less neutral.

It can mean either.

Polish palec is a general word that can refer to a finger or a toe. If you want to be specific, you can say:

• palec u ręki = finger
• palec u nogi = toe

In this sentence, because of the cooking context, a learner will probably imagine finger, but the word itself does not force that meaning by itself.

Because both are time adverbs, not nouns.

• wczoraj = yesterday
• dziś = today

They work like English yesterday and today: you can use them directly, with no extra word needed.

So:

• Wczoraj bolał mnie palec...
• ...więc dziś gotuję...

This is normal and simple Polish time expression.

Also, dziś and dzisiaj both mean today. Dziś is just the shorter form.

Because więc joins two clauses, and in Polish it is normally preceded by a comma.

Here the sentence has two parts:

• Wczoraj bolał mnie palec
• więc dziś gotuję wolniej niż zwykle

więc means so / therefore, and the comma marks the break between the cause and the result.

So the punctuation is standard: ..., więc ...

Because gotuję comes from the imperfective verb gotować, which focuses on the process or ongoing activity of cooking.

In this sentence, the speaker is talking about how they are cooking today:

• gotuję wolniej = I am cooking more slowly

That naturally fits the imperfective.

If you used ugotuję, that would be perfective and would focus more on completing the cooking, something like I will cook / I will finish cooking.

So:

• gotuję = I am cooking / I cook
• ugotuję = I will cook completely / I will manage to cook

Here gotuję is the natural choice.

Yes. That is another very common Polish feature.

The present tense of an imperfective verb can express:

• a current action: I am cooking
• a habitual action: I cook

Context tells you which meaning is intended.

In this sentence, dziś strongly suggests a current or specific-today situation:

• więc dziś gotuję wolniej niż zwykle
  = so today I’m cooking more slowly than usual

So although gotuję could also mean I cook, here the context points to I’m cooking or I’m cooking today.

Wolniej is the comparative adverb meaning more slowly.

It comes from the adverb wolno = slowly.

So:

• wolno = slowly
• wolniej = more slowly

This is the normal Polish way to say what English expresses with more slowly.

Related forms:

• wolny = slow / free (adjective)
• wolno = slowly (adverb)
• wolniej = more slowly (comparative adverb)

So gotuję wolniej literally means I cook more slowly.

Niż means than, and zwykle means usually / as usual.

So:

• wolniej niż zwykle = more slowly than usual

This is a standard comparison structure in Polish:

• szybciej niż ja = faster than me
• lepiej niż wcześniej = better than before
• wolniej niż zwykle = more slowly than usual

You can think of zwykle here as meaning something like normally or as is usual.

Yes. Polish word order is fairly flexible, because case endings already show a lot of the grammatical relationships.

For example, you could also hear:

• Wczoraj mnie bolał palec, więc dziś gotuję wolniej niż zwykle.
• Dziś gotuję wolniej niż zwykle, bo wczoraj bolał mnie palec.

These versions are still understandable, but the emphasis shifts a little.

The original sentence sounds natural and neutral: Wczoraj bolał mnie palec, więc dziś gotuję wolniej niż zwykle.

No. It is a very natural choice, but not the only one.

You could also use words like:

• dlatego = therefore / that’s why
• więc = so / therefore

For example:

• Wczoraj bolał mnie palec, dlatego dziś gotuję wolniej niż zwykle.

That also works. But więc is very common, simple, and natural in everyday speech.