Prodlužovací kabel je pod stolem.

Because pod can require different cases depending on the meaning.

In this sentence, pod stolem means under the table as a location: the extension cord is already there. For location with pod, Czech uses the instrumental case.

• basic form: stůl = table
• instrumental singular: stolem

So:

• pod stolem = under the table

No. Pod changes case depending on whether you mean location or movement toward a place.

• pod + instrumental = location
  
  • Je pod stolem. = It is under the table.
• pod + accusative = motion/direction
  
  • Dám to pod stůl. = I’ll put it under the table.

This is a very common Czech pattern with prepositions like pod, nad, před, za, mezi.

Because Czech does not have articles like English.

So Prodlužovací kabel je pod stolem could mean:

• The extension cord is under the table
• An extension cord is under the table

Usually context tells you which meaning is intended.

This is something English speakers often have to get used to: Czech leaves definiteness unstated unless there is some other clue.

Prodlužovací is an adjective modifying kabel.

Czech often uses an adjective + noun structure where English uses a noun + noun structure or a fixed compound. So:

• prodlužovací kabel = literally something like extension/prolonging cable
• natural English meaning: extension cord / extension cable

Also, prodlužovací agrees with the noun in case, number, and gender, even though in this particular form the ending does not show a very obvious difference.

Because kabel is the subject of the sentence, and the subject is normally in the nominative case.

Here the structure is:

• Prodlužovací kabel = subject
• je = is
• pod stolem = under the table

So kabel stays in nominative singular.

In a normal full sentence like this, je is needed.

• je = is

Czech normally uses the present tense of být (to be) in ordinary statements:

• Kabel je pod stolem.

You may sometimes see the verb omitted in headlines, notes, or very informal styles, but in standard neutral Czech this sentence should include je.

Yes. Czech word order is fairly flexible because the cases show what each word is doing.

The sentence:

• Prodlužovací kabel je pod stolem.

is a neutral way to say it.

But you could also say:

• Pod stolem je prodlužovací kabel.

This puts more focus on where it is, or introduces what is under the table.

So the grammar still works, but the emphasis changes.

A rough pronunciation guide is:

pro-dloo-zho-VA-tsee KA-bel ye pot STO-lem

A few important points:

• ž sounds like the s in measure
• c sounds like ts
• j sounds like English y
• je sounds like ye
• long vowels matter:
  • á is longer than a
  • í is longer than i

A more IPA-like version is:

[ˈprodluʒovaːtsiː ˈkabl̩ jɛ pot ˈstolɛm]

Yes, it is a normal and clear standard expression.

Depending on context, Czech speakers may also use more informal or shorter words, but prodlužovací kabel is perfectly natural and easy for learners to understand and use.

In everyday speech, you may also hear:

• prodlužka = an informal short form for an extension cord / extension lead

So:

• prodlužovací kabel = standard, explicit
• prodlužka = common informal everyday word

Kabel is masculine inanimate.

Yes, that matters in Czech because adjectives and some other words must agree with the noun. In this sentence, the agreement is not very dramatic on the surface, but grammatically it is still there.

So the noun phrase is:

• prodlužovací kabel

where the adjective matches the noun in:

• gender
• number
• case

This is one reason Czech word endings are so important.