Plyn je levný.

Roughly:

• Plyn ≈ plin, but with the Czech y, which is not exactly the same as English i
• je = ye
• levný ≈ lev-nee

A more careful guide:

• Czech stress is usually on the first syllable of each word: PLYN je LEV-ný
• y in plyn is a Czech vowel that English does not really have as a separate sound in the same way
• ý in levný is a long vowel, so you hold it a little longer than a short y

If you want a simple learner pronunciation, PLIN ye LEV-nee is close enough to start with.

Je is the 3rd person singular present form of the verb být, meaning to be.

So:

• já jsem = I am
• ty jsi = you are
• on/ona/ono je = he/she/it is

In Plyn je levný, je means is.

Because Czech adjectives must agree with the noun they describe.

Here, plyn is:

• masculine
• singular
• nominative

So the adjective also takes the matching form:

• masculine singular nominative: levný

Compare:

• levný plyn = cheap gas
• levná voda = cheap water
• levné auto = cheap car

So the ending changes depending on the noun.

Plyn is masculine inanimate.

One reason learners guess this is that many Czech nouns ending in a consonant are masculine. That is not a perfect rule, but it works often.

Since plyn is masculine singular, the adjective is levný, not levná or levné.

Because those forms would agree with different genders.

• levný = masculine singular
• levná = feminine singular
• levné = neuter singular, or also some plural uses

Since plyn is masculine singular, the correct form is levný.

Because Czech does not use articles like English does.

So Plyn je levný can mean:

• Gas is cheap
• The gas is cheap

The exact meaning depends on context.

English forces you to choose a/the sometimes, but Czech usually does not.

In normal standard Czech, no: you keep je in a sentence like this.

So:

• Plyn je levný. = correct standard Czech

Just Plyn levný would sound incomplete or nonstandard in ordinary usage.

This is important because some learners know languages where the present tense of to be can be omitted, but in Czech it is normally expressed here.

Yes. Czech word order is fairly flexible, but different orders can sound more or less natural depending on emphasis.

The neutral order is:

• Plyn je levný.

You might also hear:

• Levný je plyn.

But that sounds marked or emphatic, something like It’s gas that is cheap or Cheap is the gas in a very literal sense.

So for a basic statement, Plyn je levný is the best version to learn first.

Not always.

Czech plyn usually means:

• gas as a substance
• natural gas / gas supply / fuel gas

But it does not normally mean gasoline/petrol in the American English sense of gas.

For gasoline, Czech uses benzín.

So be careful: English gas can mean more than one thing, but Czech usually separates those meanings more clearly.

Mostly, yes. Levný means cheap/inexpensive.

It is the normal adjective for something that costs little money.

Examples:

• levný byt = a cheap apartment
• levné jídlo = cheap food
• Plyn je levný. = Gas is cheap.

Depending on context, cheap in English can also mean low-quality in a negative way. Czech levný can sometimes suggest that too, but its basic meaning is simply inexpensive.

The dictionary form is levný.

For Czech adjectives, dictionaries usually list the masculine singular nominative form as the base form.

So if you look it up, you will find:

• levný = cheap

Then you learn the other forms from that base:

• levná
• levné
• and the other case forms later

It is in the nominative case, because it is the subject of the sentence.

In Plyn je levný:

• plyn = the thing being talked about, so nominative
• levný matches it in nominative singular masculine

This is one reason the sentence is a useful beginner example: both the noun and adjective are in straightforward nominative forms.

It is an adjective.

It describes the noun plyn.

If you wanted an adverb, Czech would use a different form:

• levně = cheaply

So:

• Plyn je levný. = Gas is cheap.
• Prodává se levně. = It is sold cheaply.

That -ě form is typical for many Czech adverbs derived from adjectives.