Należność jest wysoka.

Należność is a noun, and it is feminine.

That matters because adjectives in Polish must agree with the noun in gender, number, and case. Here, since należność is feminine singular, the adjective appears as wysoka.

This noun is often used in formal, financial, accounting, or legal contexts. It can mean something like an amount due, a receivable, or a sum owed, depending on context.

Because wysoka has to agree with należność.

• należność = feminine singular
• so the adjective must also be feminine singular
• therefore: wysoka

Compare:

• wysoki rachunek = a high bill/account, masculine
• wysoka należność = a high amount due, feminine
• wysokie wynagrodzenie = high pay/remuneration, neuter

So this is a standard example of adjective agreement in Polish.

Both należność and wysoka are in the nominative singular.

The structure is:

• należność = subject, nominative
• jest = is
• wysoka = predicate adjective

After być (to be), Polish commonly uses the adjective in the nominative when describing the subject:

• Dom jest duży.
• Kawa jest gorąca.
• Należność jest wysoka.

So nothing unusual is happening here grammatically.

In a normal full sentence, jest is used because Polish does not usually omit the present tense of to be in standard sentences.

So:

• Należność jest wysoka. = normal complete sentence

You might sometimes see omission in:

• headings
• notes
• labels
• very compressed style

For example, in a table or report, someone might write something like Należność wysoka, but that is not the neutral full-sentence version.

For a learner, the safe standard form is:

Należność jest wysoka.

Because Polish has no articles.

English distinguishes between:

• a high amount due
• the amount due is high

Polish does not have separate words for a/an/the. The meaning is understood from context.

So Należność jest wysoka could be understood in English in different ways depending on context, for example:

• The amount due is high
• This receivable is high
• The payment due is high

The lack of an article is completely normal in Polish.

It is understandable, but it sounds more formal or administrative/business-like than many everyday alternatives.

You are especially likely to see należność in:

• invoices
• banking
• accounting
• legal or official documents

In everyday conversation, people might more often use a different word depending on what they mean, such as:

• rachunek = bill
• opłata = fee/payment
• kwota = amount
• dług = debt

So the sentence is natural, but it has a slightly formal tone.

These words overlap a bit, but they are not the same.

• należność: an amount due, a receivable, a sum owed; fairly formal
• dług: a debt; stronger and more personal/financial
• rachunek: a bill, check, or account, depending on context
• opłata: a fee or payment
• kwota: an amount/sum

So Należność jest wysoka does not necessarily mean exactly the same thing as:

• Dług jest wysoki
• Rachunek jest wysoki
• Opłata jest wysoka

Each one points to a slightly different situation.

Yes, but the most neutral order is:

Należność jest wysoka.

Polish word order is more flexible than English, because endings carry a lot of grammatical information. Still, changing the order changes the focus or emphasis.

For example:

• Należność jest wysoka. = neutral
• Wysoka jest należność. = marked, emphasizing high
• Jest wysoka należność. = unusual in ordinary speech

So as a learner, you should treat Należność jest wysoka as the standard version.

A rough guide:

• należność ≈ na-LEZH-noshch
• jest ≈ yest
• wysoka ≈ vih-SO-ka or more accurately with Polish y

A few helpful points:

• ż sounds like the s in measure
• w sounds like English v
• j sounds like English y
• ść at the end of należność is a soft consonant cluster that English does not have exactly

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

• na-LEŻ-ność
• wy-SO-ka

Yes. Wysoki / wysoka / wysokie literally means high, but in Polish, just as in English, it is often used for things like:

• prices
• fees
• amounts
• bills
• salaries
• numbers

So here wysoka is perfectly natural and means something like:

• high
• large
• substantial

It does not necessarily mean physically tall here. The context tells you it refers to amount or level.

The plural would be:

Należności są wysokie.

Changes:

• należność → należności = plural
• jest → są = are
• wysoka → wysokie = plural adjective form

So:

• Należność jest wysoka. = The amount due is high.
• Należności są wysokie. = The amounts due are high.