Learn Hardcore Polish: W niedzielę mamy rodzinny obiad i spotkanie w ogrodzie. - On Sunday we have a family lunch and a gathering in the garden.

When w means “on (a day)” and refers to time, it takes the accusative case.
Niedziela (Sunday) is a feminine noun. Its accusative singular form is niedzielę.

So:

W niedzielę = on Sunday (time → accusative)
W niedzieli would be locative case and is used in some abstract expressions (e.g. in religious language), not for normal “on Sunday” time expressions.
W niedziela is simply ungrammatical (no case ending).

Compare:

W poniedziałek – on Monday (accusative)
We wtorek – on Tuesday (accusative; we is just a variant of w used for easier pronunciation)

Does W niedzielę mean “this Sunday” or “on Sundays (in general)”?

On its own, W niedzielę can mean either, depending on context:

This / that specific Sunday:
W niedzielę mamy rodzinny obiad… – This Sunday we’re having a family lunch…
Regular habit on Sundays (if the wider conversation makes it clear):
W niedzielę mamy rodzinny obiad – On Sundays we have a family lunch.

If you want to be explicit:

W tę niedzielę mamy… – This Sunday we have… (one specific upcoming Sunday)
W każdą niedzielę mamy… – Every Sunday we have… (habit)

Why is mamy used here? Could I say jemy instead?

Mamy is the 1st person plural of mieć – to have.

Mamy rodzinny obiad literally = We have a family lunch.

Using mieć with events is very common in Polish to mean we’re having / we’re organizing / we’re doing something:

Mamy spotkanie – We’re having a meeting.
Mamy imprezę – We’re having a party.

You could say:

W niedzielę jemy obiad z rodziną. – On Sunday we eat lunch with the family.

But it focuses more on the eating itself.
Mamy rodzinny obiad focuses on the event as something planned/organized in your schedule.

There is no word for “a” or “the”. How do I know if it means a family lunch or the family lunch?

Polish has no articles (no words like a/an/the).

The sentence W niedzielę mamy rodzinny obiad can translate as:

On Sunday we have *a family lunch*
or
On Sunday we have *the family lunch*

The choice of a/the in English depends on context, not on anything explicit in Polish.

Polish often leaves this kind of detail to:

Previous context in the conversation
The listener’s common sense / shared knowledge

Why is it rodzinny obiad and not obiad rodzinny?

In Polish, the default position of an adjective is before the noun:

rodzinny obiad – a family lunch
stary dom – an old house
ciekawa książka – an interesting book

Obiad rodzinny is also grammatically possible, but:

It sounds more formal, descriptive, or contrastive, as if you’re classifying the lunch:
- For example, in a list: obiad służbowy, obiad rodzinny, obiad świąteczny…
In normal everyday speech, rodzinny obiad is the natural choice and also feels more like a set phrase: family lunch/dinner.

Is rodzinny obiad a fixed expression? Could I also say obiad z rodziną?

Yes, rodzinny obiad is a very common collocation and sounds natural.

You can also say obiad z rodziną:

rodzinny obiad – literally family lunch, stresses the type/nature of the event.
obiad z rodziną – lunch with (the) family, stresses who you’re with.

Often they are interchangeable:

W niedzielę mamy rodzinny obiad.
W niedzielę mamy obiad z rodziną.

Both are good. The first sounds a bit more like a traditional, perhaps special, family meal; the second just states you’re eating with family.

Does obiad mean “lunch” or “dinner”?

In Polish, obiad is the main hot meal of the day, usually eaten in the afternoon.

Depending on culture and schedule, in English it can correspond to:

Lunch (if eaten around 1–3 p.m.)
Dinner (if it is the main big meal of the day, even if earlier)

So rodzinny obiad could be translated as:

family lunch, or
family dinner

Translators usually choose lunch, but the exact word depends on your target variety of English and the time of day implied.

What case is w ogrodzie, and why isn’t it w ogród?

W ogrodzie uses the locative case.

The noun is ogród (garden).
Locative singular of ogród is ogrodzie.

Preposition w has different cases depending on meaning:

w
- locative → location (where something is):
  - w ogrodzie – in the garden
  - w domu – in the house
w
- accusative → movement into or time:
  - iść w góry – to go into the mountains
  - w niedzielę – on Sunday

So:

w ogrodzie = in the garden (place → locative)
w ogród is wrong in standard Polish in this meaning.

Why is it w ogrodzie and not na ogrodzie?

Standard Polish uses:

w ogrodzie – in the garden

Some speakers, especially regionally, say na ogrodzie, but this is considered dialectal/colloquial and is not standard.

The general pattern:

w
- locative → inside something (in a building, in a space)
  - w domu – in the house
  - w parku – in the park
  - w ogrodzie – in the garden
na
- locative → on a surface, or certain set phrases:
  - na stole – on the table
  - na podwórku – in the yard
  - na ulicy – in the street

So for a normal garden, w ogrodzie is the neutral, standard choice.

Can I change the word order, for example: Mamy w niedzielę rodzinny obiad i spotkanie w ogrodzie?

Yes. Polish word order is relatively flexible, and all of these are possible:

W niedzielę mamy rodzinny obiad i spotkanie w ogrodzie.
Mamy w niedzielę rodzinny obiad i spotkanie w ogrodzie.
Rodzinny obiad i spotkanie w ogrodzie mamy w niedzielę.

The basic neutral version is the original one, with the time expression at the beginning:

W niedzielę mamy…

Moving elements around mostly changes emphasis:

Starting with Mamy highlights the fact that we have (something planned).
Putting w niedzielę later may sound like an afterthought:
We have a family lunch and a meeting in the garden – on Sunday.

But grammatically they’re all acceptable.

What exactly does spotkanie mean here? Is it like a formal “meeting”?

Spotkanie is a noun formed from the verb spotkać (się) – to meet.

It can mean both:

a formal meeting (a work meeting, an official appointment), and
an informal get‑together (friends meeting in a café, family meeting in the garden).

In this context, with rodzinny obiad i spotkanie w ogrodzie, it probably means a family get‑together / gathering in the garden, not a formal business meeting.

If you want to stress informality, you can add more detail:

spotkanie rodzinne w ogrodzie – a family gathering in the garden
spotkanie z przyjaciółmi w ogrodzie – a meeting with friends in the garden

How would I say “On Sunday we have a family lunch with the family in the garden” more explicitly?

You can make the sentence more explicit by adding z rodziną:

W niedzielę mamy rodzinny obiad z rodziną i spotkanie w ogrodzie.
- On Sunday we have a family lunch with the family and a meeting in the garden.

Or, if you don’t want rodzinny twice:

W niedzielę mamy obiad z rodziną i spotkanie w ogrodzie.
- On Sunday we have lunch with the family and a meeting in the garden.

Both are natural. The original sentence already implies family context through rodzinny obiad, so native speakers rarely feel the need to add z rodziną unless they want to be very clear.