I barnvagnen ligger en liten matsäck och en filt.

Swedish often puts the place first when that is the topic of the sentence. Here, I barnvagnen means in the stroller / pram, and the speaker is setting the scene first.

So the sentence structure is roughly:

• I barnvagnen = place
• ligger = verb
• en liten matsäck och en filt = what is there

This is very natural in Swedish.

This is because of the Swedish V2 rule: the finite verb usually comes in second position in main clauses.

Since I barnvagnen is placed first, the verb ligger must come next:

• I barnvagnen ligger en liten matsäck och en filt.

If the subject came first, you could have:

• En liten matsäck och en filt ligger i barnvagnen.

Both are grammatical, but the focus is slightly different.

Barnvagn means stroller, pram, or baby carriage.

The form barnvagnen is the definite singular form, meaning the stroller / the pram.

Breakdown:

• barnvagn = stroller, pram
• barnvagnen = the stroller, the pram

In Swedish, definiteness is often added as a suffix at the end of the noun.

I usually means in or inside.

So I barnvagnen means in the stroller. This suggests the items are inside it.

A learner might compare this with på, which often means on. Swedish sometimes uses prepositions differently from English, but here i is the natural choice because the things are inside the stroller.

Ligger is the present tense of ligga, which literally means lie.

Swedish often uses position verbs like:

• ligga = lie
• stå = stand
• sitta = sit

for objects depending on how they are located.

Here, the food and blanket are understood as lying in the stroller, so ligger sounds natural.

You could also hear:

• Det finns en liten matsäck och en filt i barnvagnen.

That means something like There is a small snack/lunch and a blanket in the stroller. It is also correct, but ligger gives a more physical sense of where the objects are.

Both matsäck and filt are en-words (common gender nouns), so they take en in the singular indefinite form.

• en matsäck
• en filt

That is why the sentence says:

• en liten matsäck
• en filt

If a noun were an ett-word, it would take ett instead.

The adjective changes according to the noun it describes.

Since matsäck is an en-word, the adjective takes the en-word form:

• en liten matsäck

Compare:

• ett litet barn = a small child

So:

• liten is used with en-words
• litet is used with ett-words

Liten is also a slightly irregular adjective, so it is worth memorizing:

• en liten
• ett litet
• små in the plural

Matsäck usually means food that you bring with you, such as:

• a packed lunch
• a snack to take on an outing
• picnic food

It does not usually mean just any meal. It suggests prepared food carried along for later.

So in this sentence, en liten matsäck could be understood as something like a small packed snack/lunch.

No. Grammatically, liten only describes matsäck.

So the phrase means:

• a small packed lunch/snack and a blanket

It does not automatically mean the blanket is small too.

If both were small, Swedish would usually say:

• en liten matsäck och en liten filt

In modern Swedish, verbs do not change according to number or person the way they do in some other languages.

So the present tense form ligger is used whether the subject is singular or plural:

• En filt ligger där. = A blanket is lying there.
• En filt och en matsäck ligger där. = A blanket and a packed lunch are lying there.

The verb stays the same.

Yes, absolutely. That is also a natural Swedish sentence.

• Det ligger en liten matsäck och en filt i barnvagnen.

This is close to English There is/are a small packed lunch and a blanket in the stroller.

The version with I barnvagnen first puts more emphasis on the location. The version with Det ligger is a more neutral way to introduce what is there.