Po kolacji myję miskę gąbką.

Because po requires the locative case when it means after.

• basic form: kolacja = dinner
• locative singular: kolacji

So:

• po kolacji = after dinner

This is a very common pattern in Polish:

• po pracy = after work
• po szkole = after school
• po obiedzie = after lunch

Myję is the 1st person singular present tense form of myć, which means to wash.

So:

• myć = to wash
• myję = I wash / I am washing

Polish present tense often covers both English simple present and present continuous, depending on context.

So myję miskę can mean:

• I wash the bowl
• I am washing the bowl

Because Polish usually does not need subject pronouns when the verb ending already shows who is doing the action.

Here, myję already means I wash. So ja is unnecessary unless you want emphasis.

• Myję miskę. = I’m washing the bowl.
• Ja myję miskę. = I’m washing the bowl. / I wash the bowl.

Adding ja often gives contrast or emphasis.

Because miska is the direct object of the verb myję, so it goes into the accusative case.

• nominative: miska = bowl
• accusative: miskę = bowl (as the thing being washed)

So:

• miska = a bowl / the bowl as subject
• myję miskę = I wash the bowl

This is very typical in Polish: feminine nouns ending in -a often change to -ę in the accusative singular.

Because gąbką is in the instrumental case.

In this sentence, the sponge is the tool used to do the washing, so Polish uses the instrumental:

• nominative: gąbka = sponge
• instrumental: gąbką = with a sponge / using a sponge

So:

• myję miskę gąbką = I wash the bowl with a sponge

Because Polish often expresses with, by means of, using through the instrumental case, without adding a separate preposition.

So English:

• with a sponge

becomes Polish:

• gąbką

This is a very important pattern:

• Piszę długopisem. = I write with a pen
• Kroję nożem. = I cut with a knife
• Myję miskę gąbką. = I wash the bowl with a sponge

Be careful: z can also mean with, but usually in the sense of together with someone/something, not as an instrument.

• Idę z siostrą. = I’m going with my sister
• myję gąbką = I wash with a sponge

Normally, no. The cases make the roles clear:

• miskę = accusative → the thing being washed
• gąbką = instrumental → the tool used for washing

So the natural reading is:

• I wash the bowl with a sponge

If you wanted to say I wash the sponge, you would say:

• Myję gąbkę.

Here gąbkę is accusative, so the sponge becomes the direct object.

It is present tense.

The verb myć is imperfective, so its present forms describe:

• present actions
• habitual actions

Examples:

• Teraz myję miskę. = I’m washing the bowl now.
• Po kolacji zawsze myję miskę. = After dinner I always wash the bowl.

To express a completed future action, Polish usually uses the perfective verb:

• umyję = I will wash / I will have washed

So:

• Po kolacji myję miskę. = After dinner I wash / I’m washing the bowl.
• Po kolacji umyję miskę. = After dinner I will wash the bowl.

This is a question of aspect.

• myć = imperfective → focuses on the process, repetition, or general action
• umyć = perfective → focuses on completing the action

So:

• myję miskę = I am washing / I wash the bowl
• umyję miskę = I will wash the bowl completely

In a simple sentence like this, myję sounds natural if you are describing an action or habit. If the speaker wants to stress completion, umyję would be more likely.

Yes. Polish word order is fairly flexible because cases show grammatical roles.

The neutral order here is:

• Po kolacji myję miskę gąbką.

But other orders are possible, depending on emphasis:

• Miskę myję gąbką po kolacji.
• Gąbką myję miskę po kolacji.

These still mean roughly the same thing, but the emphasis changes.

In most ordinary situations, the original sentence sounds natural and straightforward.

A learner may notice the nasal vowels.

• ą and ę are Polish nasal vowels, but their pronunciation changes depending on the following sound.
• In actual speech, they are often not pronounced as fully nasal vowels in every environment.

In this sentence:

• miskę: final ę is often pronounced less strongly nasal, sometimes almost like e in casual speech
• gąbką: before b, ą is often pronounced something like om
• kolacji has no nasal vowel, but the cji cluster may need practice

A rough learner-friendly pronunciation could be:

• Po kolacji myję miskę gąbką
• approximately: po ko-LA-tsyi MI-ye MIS-ke GOMB-kong

That is only an approximation, but it helps show what is happening.

Its core meaning is bowl, but like many nouns, it can refer to different kinds of bowls depending on context:

• a kitchen bowl
• a dog bowl
• a washbasin-like bowl in some contexts

In this sentence, since it is being washed with a sponge and the phrase is after dinner, the most natural reading is simply a bowl used for food.