W środę idę do lekarza po pracy.

Because after w when talking about on + day of the week, Polish uses the accusative case.

• Basic form: środa = Wednesday
• Accusative singular: środę

So:

• w środę = on Wednesday

This is a common pattern:

• w poniedziałek = on Monday
• we wtorek = on Tuesday
• w środę = on Wednesday

Also note that Polish weekday names are normally not capitalized.

In Polish, the present tense of an imperfective verb is often used for a planned or scheduled future action, especially when there is a time expression such as w środę.

So idę literally looks like I am going, but in context it can mean:

• I’m going on Wednesday
• I’m going this Wednesday

This is very natural in Polish, just like English can say I’m going to the doctor on Wednesday after work.

These are related, but they are not interchangeable.

• idę = I am going / I’m going
  
  • one specific trip, happening now or planned
• pójdę = I will go
  
  • perfective, focuses more on the completed future act
• chodzę = I go / I walk / I go regularly
  
  • habitual or repeated action

So:

• W środę idę do lekarza = I’m going to the doctor on Wednesday.
• W środę pójdę do lekarza = I will go to the doctor on Wednesday.
  Slightly more definite or one-off in feeling.
• Chodzę do lekarza po pracy = I go to the doctor after work regularly / habitually.
  This changes the meaning a lot.

After the preposition do, Polish normally uses the genitive case.

• dictionary form: lekarz = doctor
• genitive singular: lekarza

So:

• do lekarza = to the doctor

This is the normal way to say you are going to see a doctor.

A useful contrast:

• idę do lekarza = I’m going to the doctor
• jestem u lekarza = I’m at the doctor’s / at the doctor

So do expresses movement toward the destination, while u expresses being at someone’s place.

Because po in the meaning after takes the locative case.

• basic form: praca = work
• locative singular: pracy

So:

• po pracy = after work

This is a very common expression in Polish.

Be careful: po can mean different things in different contexts, but here it simply means after.

Yes. Polish word order is more flexible than English word order because grammatical endings show the function of the words.

W środę idę do lekarza po pracy is a very natural neutral sentence.

But you could also say:

• Idę do lekarza w środę po pracy.
• Po pracy idę do lekarza w środę.
• Do lekarza idę w środę po pracy.

These versions are all possible, but they may shift the emphasis a little.

The original sentence sounds very natural if you want to start with the time: On Wednesday, I’m going to the doctor after work.

Because Polish often drops subject pronouns when they are already clear from the verb form.

• idę already means I go / I’m going

So ja is not necessary.

You could say:

• Ja idę do lekarza...

but that usually adds emphasis, for example:

• I’m the one going to the doctor
• As for me, I’m going to the doctor

In neutral sentences, Polish usually leaves ja out.

In Polish, names of:

• weekdays
• months
• languages
• nationalities used as nouns in some contexts

are usually written with lowercase letters, unless they begin a sentence.

So:

• w środę = correct
• w Środę = not correct in normal spelling

This is different from English, where Wednesday must be capitalized.

Originally, iść / idę is the verb for going on foot, but in everyday Polish it is often used more broadly for going somewhere, especially for appointments or planned events.

So:

• Idę do lekarza is perfectly natural even if the sentence does not focus on the method of transport.

If you specifically want to say you are going by vehicle, Polish often uses jechać:

• W środę jadę do lekarza po pracy = I’m going to the doctor on Wednesday after work, probably by car/bus/etc.

But in many everyday situations, idę do lekarza is the normal choice.

It can cover both ideas in practice.

Literally, do lekarza means to the doctor, but idiomatically it usually means:

• to see the doctor
• to the doctor’s office / clinic for an appointment

Polish often focuses on the person rather than explicitly naming the office or clinic.

So idę do lekarza is the normal everyday phrase.

A rough English-friendly approximation is:

• W środę ≈ v SHROH-deng

A few important points:

• w sounds like English v
• ś is a soft sh sound
• ę at the end is nasal; in normal speech it is often not pronounced as a full nasal vowel in a very careful way, so learners may hear something close to -e or -en/-eng depending on context

A more detailed breakdown of the whole sentence:

• W → v
• środę → roughly SHRO-de(n)
• idę → roughly EE-de(n)
• do → do
• lekarza → roughly le-KA-zha
• po → po
• pracy → roughly PRA-tsy

You do not need a perfect English imitation; the most important parts are:

• soft ś
• Polish r
• cz / rz / cy-type sounds in other words when relevant

No. Polish has no articles like a/an/the.

So:

• do lekarza can mean to a doctor or to the doctor
• po pracy can mean after work

The exact meaning depends on context.

That is why Polish sentences often look shorter than their English equivalents.