Learn Hardcore Finnish: Ostoskorissa on leipää, juustoa ja talouspaperia. - In the shopping basket there is bread, cheese and kitchen paper.

So ostoskorissa literally means “in (the) shopping basket.”
Finnish normally adds a case ending instead of using a separate preposition like in.

Why does the sentence start with Ostoskorissa instead of with the things that are in it?

Finnish often uses this word order for existential sentences (sentences that introduce something’s existence or presence in a place):

[Location] + on + [thing(s)]

So:

Ostoskorissa on leipää, juustoa ja talouspaperia.
= In the shopping basket there is bread, cheese and kitchen paper.

This pattern answers “What is in/at X?” and introduces new information.
If you put the things first, like Leipää on ostoskorissa, you are slightly emphasizing the bread rather than the basket (for example, after someone asked specifically about the bread).

Why are the words leipää, juustoa and talouspaperia not in their basic forms leipä, juusto, talouspaperi?

Leipää, juustoa and talouspaperia are in the partitive singular (endings -a / -ä, -ta / -tä here simplified to -a):

leipä → leipää
juusto → juustoa
talouspaperi → talouspaperia

In this type of sentence (place + on + something), Finnish uses the partitive when you talk about:

an unspecified amount
only some of a substance or material
things seen as a mass or not individually counted

So the sentence is really saying:

“In the shopping basket there is some bread, some cheese and some kitchen paper.”

English often leaves out some, but Finnish shows this idea with the partitive ending.

So does the partitive here basically mean “some”?

Yes, that is a good practical way to think about it in this sentence.

leipää ≈ “some bread”
juustoa ≈ “some cheese”
talouspaperia ≈ “some kitchen paper / some paper towel(s)”

Finnish usually does not use a separate word like “some” in this context.
Instead, the partitive case on the noun tells you it is an indefinite / non‑whole / some amount of that thing.

When would I use the basic form (nominative) instead of the partitive in this kind of sentence?

In existential sentences (with on + a place), you normally use:

Partitive: when talking about an indefinite amount, new items, or “some of” something
Nominative: when the thing is seen as a whole, specific, or fully counted

Compare:

Ostoskorissa on leipää.
= There is (some) bread in the shopping basket.
→ Unspecified amount; we don’t care exactly which piece or how much.
Ostoskorissa on leipä.
= The bread is in the shopping basket.
→ Refers to a specific whole bread/loaf that the speakers already have in mind (something like “the bread we talked about is in the basket”).

So using the nominative here feels more like you’ve identified a particular item as the bread, the cheese, etc.

Could I say these in the plural, like leipiä, juustoja, talouspapereita?

Yes, you can, but the meaning changes slightly:

Ostoskorissa on leipää.
= There is (some) bread.
→ Bread as a mass or at least not counted (maybe slices, maybe part of a loaf).
Ostoskorissa on leipiä.
= There are (some) loaves of bread.
→ Clearly multiple separate breads (loaves, perhaps rolls), not just “bread in general.”

Similarly:

juustoa = some cheese (like a block, slices, grated cheese – not counted)
juustoja = several distinct cheeses (for example different kinds or separate pieces)
talouspaperia = some kitchen paper / paper towel (mass or material)
talouspapereita = several separate kitchen paper items (for example many rolls or packages)

So:

Partitive singular → some amount of that substance or item, seen as one “mass”.
Partitive plural → several individual items of that type.

Why is talouspaperi written as one word? In English it’s “kitchen paper” or “paper towel”.

Finnish very often creates compound nouns by joining words together:

talous = household, economy
paperi = paper
talouspaperi = literally “household paper” → kitchen paper / paper towel

As one compound word, talouspaperi refers specifically to the type of paper you use in the kitchen / household for cleaning and wiping.

So you should treat talouspaperi as a single dictionary word, not as two separate words.

Why is talouspaperia also in the partitive? I can count paper towel rolls, can’t I?

You can count them, but in this sentence Finnish is treating talouspaperi more like a material or mass rather than individual rolls.

So:

talouspaperia = some amount of kitchen paper (not focusing on how many rolls)
talouspapereita = several individual pieces/rolls/packs of kitchen paper

In everyday speech, if the exact number of rolls is not important, Finns often use talouspaperia to mean “there is (some) kitchen paper,” even though physically it’s in rolls.

Are commas and ja used the same way in lists as in English?

Mostly yes.

Items are separated by commas, and ja (and) goes before the last item:
- leipää, juustoa ja talouspaperia
  = bread, cheese and kitchen paper

There is usually no comma before ja in a simple list like this (Finnish doesn’t normally use the “Oxford comma” pattern).