What is the Polish 1-2-5 rule?

Polish nouns take three different forms after a number. 1 uses the singular, numbers ending in 2-4 (except 12-14) use a few form, and everything else uses the genitive plural. For year this gives 1 rok, 2 lata, 5 lat.

Why are 12, 13 and 14 special?

Even though they end in 2, 3 and 4, the teens 12-14 take the many form, so it is 12 lat not 12 lata. The rule checks the last two digits to catch this exception.

What does suppletive mean here?

Some Polish words switch to a different stem in the plural. The word for year is rok in the singular but lata and lat in the plural, which is why you must supply all three forms rather than adding an ending.

Can I use my own words?

Yes. Type any singular, few and many forms you like, or start from a preset such as year, hour or złoty and adjust. The selection logic stays the same.

Does anything get uploaded?

No. The rule runs locally in your browser, so your counts and words never leave the page.

Polish Plural Helper

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After a number, a Polish noun appears in one of three forms, and choosing the wrong one is one of the most common mistakes learners make. This tool applies the canonical 1-2-5 rule and even handles suppletive words like rok / lata / lat (year), where the plural uses an entirely different stem.

How it works

The tool inspects the last digit and last two digits of the count to choose a form:

n === 1                          → singular        (1 rok)
last digit 2-4, not 12-14        → few / nominative (2 lata, 24 lata)
everything else (0, 5-21, ...)   → many / genitive  (5 lat, 13 lat)

Because Polish has suppletive plurals, you provide all three forms rather than letting the tool add an ending. Presets cover common nouns, and you can override them with any words you need.

Example and notes

For rok / lata / lat: 1 gives 1 rok, 2–4 give 2 lata, and 5+ give 5 lat. The same rule decides 21 osób? No — 21 ends in 1 but is not exactly 1, so it falls into the many form: 21 osób. Watch the teens: 12 lat, not 12 lata. The selected form is labelled in the result so you can confirm the rule fired as expected.