Polski — Consonant alternations in inflection
In many Polish forms the last consonant of the stem changes before certain endings. These regular softenings (k:c, g:dz, ch:sz, t:ci, d:dzi, r:rz, ł:l) show up in the plural, in the dative and locative, and in the vocative — for example ręka/ręce, noga/nodze, student/studenci.
How it works
Before certain endings — above all the dative/locative singular, the masculine personal nominative plural, and the vocative — the final stem consonant softens according to fixed pairs: k→c, g→dz, ch→sz, t→ci, d→dzi, r→rz, ł→l. So ręka becomes ręce, student becomes studenci, and noga becomes nodze.
Examples
| Alternation | Example | Meaning and context |
|---|---|---|
| k : c | ręka → ręce | hand → hands (nominative plural) |
| g : dz | noga → nodze | leg → to/on the leg (dative/locative singular) |
| ch : sz | mucha → musze | fly → to/on the fly (dative/locative singular) |
| t : ci | student → studenci | student → students (masculine personal nominative plural) |
| d : dzi | sąsiad → sąsiedzi | neighbour → neighbours (masculine personal nominative plural) |
| r : rz | aktor → aktorzy | actor → actors (masculine personal nominative plural) |
| ł : l | stół → stole | table → on the table (locative singular) |
Good to know
The alternation is triggered by the ending, not chosen freely: the same noun keeps the hard consonant elsewhere (ręka, ręką) and softens only before the relevant endings (ręce). Learners often apply k:c and g:dz but forget that r:rz and ł:l work the same way, producing wrong forms like *aktory instead of aktorzy.