Pod łóżkiem leżą czyste skarpetki.

Because pod can take different cases, and here it describes location: under the bed.

When pod means where?, Polish uses the instrumental case:

• pod łóżkiem = under the bed

The noun łóżko changes in the instrumental singular to łóżkiem.

Compare:

• Pod łóżkiem leżą skarpetki. = The socks are under the bed. → location
• Wkładam skarpetki pod łóżko. = I put the socks under the bed. → movement toward a place, so accusative

So a useful rule is:

• pod + instrumental = location
• pod + accusative = motion/direction

Because leżeć means to lie or to be lying, so it describes the socks as being in a lying position.

• leżeć = to lie
• leżą = they lie / are lying

Since skarpetki is plural, the verb must also be plural:

• skarpetki leżą = the socks are lying

You can say:

• Pod łóżkiem są czyste skarpetki.

That means roughly There are clean socks under the bed.

But leżą is more vivid and natural if you want to describe how the socks are physically resting there.

Because the subject is skarpetki, which is plural, and the sentence is in the present tense.

The verb leżeć conjugates like this in the present:

• ja leżę = I lie
• ty leżysz = you lie
• on/ona/ono leży = he/she/it lies
• my leżymy = we lie
• wy leżycie = you (plural) lie
• one leżą = they lie

Since skarpetki is plural and non-masculine-personal, Polish uses the 3rd person plural form:

• skarpetki leżą

Because adjectives in Polish must agree with the noun in number, gender, and case.

Here:

• skarpetki is plural
• it is non-masculine-personal
• it is the subject, so it is in the nominative

So the adjective also takes the matching form:

• czyste skarpetki = clean socks

Compare:

• czysta skarpetka = a clean sock
• czyste skarpetki = clean socks

So the ending -e is there because the adjective is agreeing with a plural non-masculine-personal noun.

Because skarpetki is the subject of the sentence, so it is in the nominative plural.

The basic singular noun is:

• skarpetka = sock

Its nominative plural is:

• skarpetki = socks

In this sentence, the socks are the things doing the action of lying, so Polish uses the nominative:

• czyste skarpetki leżą

A detail that can confuse learners: for many feminine nouns, the nominative plural and accusative plural look the same. So skarpetki can appear in more than one grammatical role, but here it is clearly the subject, so it is nominative.

Polish word order is more flexible than English word order, because case endings show grammatical roles.

Starting with Pod łóżkiem puts the location first:

• Pod łóżkiem leżą czyste skarpetki.

This feels natural if you are first setting the scene, then saying what is there.

Other word orders are also possible:

• Czyste skarpetki leżą pod łóżkiem.
• Leżą pod łóżkiem czyste skarpetki.

These all mean roughly the same thing, but the focus changes:

• Pod łóżkiem... → emphasizes where
• Czyste skarpetki... → emphasizes what
• Leżą... → can sound more literary or expressive

So the given sentence is very natural, especially when answering Where are the clean socks?

Yes, absolutely.

Both are grammatical:

• Pod łóżkiem leżą czyste skarpetki.
• Pod łóżkiem są czyste skarpetki.

The difference is mainly stylistic:

• są = simply says that the socks are there
• leżą = says they are lying there

So:

• są is more neutral
• leżą is more descriptive

In everyday Polish, leżeć is very common for objects resting somewhere.

No. This is a very important point.

Pod can take:

• instrumental for location
• accusative for motion/direction

Examples:

Location:

• Pod łóżkiem leżą skarpetki. = The socks are under the bed.

Motion:

• Wsuwam skarpetki pod łóżko. = I slide the socks under the bed.

So if you are asking:

• Where? → usually instrumental
• Where to? / in what direction? → usually accusative

Because Polish does not have articles like English a/an and the.

So:

• łóżko can mean a bed or the bed
• skarpetki can mean socks, the socks, or sometimes some socks

The exact meaning depends on context.

In this sentence, English often translates it as:

• The clean socks are lying under the bed or
• There are clean socks under the bed

Polish leaves that distinction to context rather than using articles.

A rough pronunciation guide:

• ł sounds like English w
• ó sounds like u in rule
• ż sounds like the s in measure
• ę is a nasal vowel, often sounding a bit like en/em depending on what follows
• ą is also nasal

Very roughly:

• łóżkiem ≈ WOOZH-kyem
• leżą ≈ LEH-zhaw (with a nasal final vowel)

A more natural whole-sentence approximation:

• Pot WOOZH-kyem LEH-zhaw CHI-steh skar-PET-kee

That is only approximate, but it helps with the main sounds.

Yes. In Polish, plural agreement often distinguishes:

• masculine personal nouns
• non-masculine-personal nouns

Skarpetki is non-masculine-personal, so it uses forms like:

• czyste
• leżą

Compare with a masculine-personal noun:

• mężczyźni = men
• wysocy mężczyźni stoją = tall men are standing

But with non-masculine-personal nouns:

• czyste skarpetki leżą

This distinction matters especially in adjectives, past tense, and some numerals.

Usually it describes a state: the socks are lying under the bed.

In Polish, the present tense of verbs like leżeć can correspond to English:

• lie
• are lying

So the sentence can be understood as:

• The clean socks lie under the bed or more naturally in English:
• The clean socks are lying under the bed

It does not necessarily mean the socks are actively moving. It simply describes their position.