W przychodni czekam przed gabinetem.

Because the preposition w normally requires the locative case when it means in / at a place.

The base noun is przychodnia = clinic / medical center / outpatient clinic.
Its locative singular form is przychodni.

So:

• przychodnia = dictionary form
• w przychodni = in / at the clinic

This is a very common pattern with feminine nouns ending in -a.

Przychodnia usually means a clinic, medical center, or outpatient medical facility where patients go for appointments, checkups, or basic treatment.

It is not exactly the same as:

• szpital = hospital
• gabinet lekarski = doctor’s office / consulting room
• klinika = clinic, but often a larger or more specialized institution

In this sentence, przychodnia is the building or facility, while gabinet is the specific room inside it.

Because the preposition przed can mean in front of in a physical, spatial sense, and when it describes location, it takes the instrumental case.

The base noun is gabinet.
Its instrumental singular form is gabinetem.

So:

• gabinet = office / consulting room
• przed gabinetem = in front of the office / outside the consulting room

This is why the ending changes from -et to -etem.

In a medical context, gabinet usually means a doctor’s office, consulting room, or exam room.

So here it does not mean a piece of furniture like cabinet in English.
It means the room where the doctor sees patients.

That is a very common false-friend issue for English speakers.

Czekam is the 1st person singular present tense form of the verb czekać = to wait.

So:

• czekać = to wait
• czekam = I wait / I am waiting

Polish often uses the simple present where English may prefer I am waiting.

Other forms for comparison:

• czekasz = you are waiting
• czeka = he/she/it is waiting
• czekamy = we are waiting

Because in Polish, the verb ending usually already shows who the subject is.

In czekam, the ending -am tells you it means I.
So ja is usually unnecessary unless you want emphasis or contrast.

For example:

• Czekam. = I’m waiting.
• Ja czekam, a on wchodzi. = I’m waiting, and he is going in.

So omitting ja is completely normal.

Yes. Polish word order is fairly flexible because the endings carry a lot of the grammatical information.

W przychodni czekam przed gabinetem is natural and clear, but you could also say:

• Czekam przed gabinetem w przychodni.
• Przed gabinetem czekam w przychodni.

These versions are all understandable, but they may shift the emphasis slightly.

For example:

• W przychodni first puts focus on where generally
• Przed gabinetem first puts focus on the exact spot

The original sentence sounds natural and neutral.

Yes. Przed can mean either:

• in front of = spatial meaning
• before = time meaning

In this sentence, it clearly means in front of, because it is followed by a place noun: gabinetem.

Examples:

• przed gabinetem = in front of the office
• przed wizytą = before the appointment

So the meaning depends on context.

Because after przed, Polish uses:

• instrumental for location: in front of
• also instrumental in many other static expressions with certain prepositions

So:

• przed gabinetem = in front of the office
• przed domem = in front of the house
• przed szkołą = in front of the school

This is something you usually just learn together with the preposition:
przed + instrumental for location.

Sometimes yes, depending on the speaker and context.

• przed gabinetem = in front of the office
• pod gabinetem = literally under/by the office, but in everyday Polish it can also mean outside the office door or right by the office

In medical settings, some speakers might say czekam pod gabinetem, especially when they mean I’m waiting just outside the doctor’s room.

So both can occur, but:

• przed gabinetem sounds more literally in front of
• pod gabinetem often sounds more idiomatic for waiting outside someone’s room

Yes, but it would mean something different.

• przed gabinetem = in front of the office / outside the room
• w gabinecie = in the office / inside the room

So if you are waiting in the corridor outside the doctor’s room, przed gabinetem fits.
If you are already inside the doctor’s office, then w gabinecie would be correct.

A helpful approximate pronunciation is:

v pshi-HOD-nyee CHE-kam pshet ga-bi-NE-tem

A few notes:

• w is pronounced like English v
• przy sounds roughly like pshi
• ch sounds like a hard h / kh
• cz sounds like ch in chop
• rz here sounds like a soft zh/sh-like sound depending on context, but in przed it is pronounced close to pshet
• stress in Polish usually falls on the second-to-last syllable

So:

• przychodni → przy-CHOD-ni
• gabinetem → ga-bi-NE-tem

Yes, it is natural and correct.

It sounds like something a patient might say to describe where they are:

• W przychodni czekam przed gabinetem.

A very natural alternative would also be:

• Czekam przed gabinetem w przychodni.

Both are good. The original sentence is perfectly fine and grammatical.