W lodówce mam szynkę, sałatę i trochę śmietany.

Because w meaning in normally takes the locative case when it answers the question where?

• dictionary form: lodówka = fridge
• after w: w lodówce = in the fridge

So this is a case change, not a different word.

In Polish, subject pronouns are often omitted when the verb already makes the subject clear.

• mam = I have
• masz = you have
• ma = he/she/it has

Because mam already clearly means I have, Polish usually does not need ja. You could say Ja mam, but that adds emphasis, something like I do have.

Because they are the direct objects of mam (I have), so they are in the accusative case.

Their basic forms are:

• szynka = ham
• sałata = lettuce

After mam, they become:

• mam szynkę
• mam sałatę

This is very common with many feminine nouns ending in -a:
-a often changes to -ę in the accusative singular.

Because trochę (a little, some) requires the following noun to be in the genitive case.

• basic form: śmietana
• after trochę: śmietany

So:

• mam śmietanę = I have cream / sour cream
• mam trochę śmietany = I have some / a little cream

This pattern is very common in Polish:

• trochę wody = some water
• trochę chleba = some bread
• trochę sera = some cheese

In everyday Polish, śmietana often refers to what English speakers would call sour cream, especially in food contexts.

That means translations can vary depending on context:

• śmietana = cream / sour cream
• śmietanka = cream, especially lighter liquid cream
• bita śmietana = whipped cream

So if you see śmietana in a fridge sentence, many learners should think sour cream first unless the context says otherwise.

They are different words:

• sałata = lettuce
• sałatka = salad

So in this sentence, sałatę comes from sałata, meaning lettuce, not a prepared salad.

Examples:

• Kupuję sałatę. = I’m buying lettuce.
• Robię sałatkę. = I’m making a salad.

Literally, mam means I have.

So the sentence literally means something like:

• In the fridge I have ham, lettuce, and some cream.

In natural English, depending on context, you might sometimes say:

• There’s ham, lettuce, and some cream in the fridge.

But the Polish sentence still uses mam, so the speaker is talking about what they have available. If Polish wanted a more neutral there is/there are structure, it could use jest/są, for example:

• W lodówce jest szynka... = There is ham in the fridge...

Yes. That is also correct.

Both are natural, but the word order changes the emphasis a little:

• W lodówce mam... = In the fridge, I have...
• Mam w lodówce... = I have ... in the fridge.

Putting w lodówce first sets the scene or emphasizes the location. Polish word order is flexible, but not random: moving things changes focus and emphasis.

Because Polish has no articles like English a/an/the.

So:

• szynkę can mean ham, a ham, or the ham, depending on context
• sałatę can mean lettuce, some lettuce, the lettuce, depending on context

Polish relies on context instead of articles.

In this sentence, trochę already gives the idea of some for śmietany, so that one is expressed explicitly.

Because the sentence lists two regular direct objects and then one quantity expression.

• szynkę and sałatę are simple objects after mam
• trochę śmietany is a quantity phrase: some cream

So the structure is:

• mam szynkę
• mam sałatę
• mam trochę śmietany

The third item behaves differently because of trochę, which changes the case of the noun after it.

A rough English-style approximation is:

v lo-DOOF-tseh mam SHIN-keh, sa-WAH-teh ee TROH-heh shmye-TAH-nih

A few helpful notes:

• w is usually like English v
• sz sounds like sh
• ś is a softer sound than sh
• c in lodówce sounds like ts
• ę is a nasal vowel in spelling, but in normal speech its pronunciation often changes depending on what follows

Stress in Polish is usually on the second-to-last syllable:

• lo-DÓW-ce
• SZYN-kę
• sa-ŁA-tę
• śmie-TA-ny

For a learner, getting the stress right is more important at first than making the nasal vowels perfect.