Gaeilge · Séimhiú agus Urú
Initial consonant mutation is a hallmark of Celtic linguistics. Words systematically alter their opening consonant based on what precedes them—whether possessive pronouns, prepositions, numbers, or grammatical gender.
| Radical (Base) | Mutated Form | Blocked Exceptions |
|---|---|---|
| b | bh | None |
| c | ch | None |
| d | dh | None |
| f | fh | None |
| g | gh | None |
| m | mh | None |
| p | ph | None |
| s | sh | Does not mutate before: sc, sf, sm, sp, st |
| t | th | None |
| Radical (Base) | Mutated Form | Blocked Exceptions |
|---|---|---|
| b | mb | None |
| c | gc | None |
| d | nd | None |
| f | bhf | None |
| g | ng | None |
| p | bp | None |
| t | dt | None |
| vowel | n- | None |
| Radical (Base) | Mutated Form | Blocked Exceptions |
|---|---|---|
| vowel | h | None |
| Radical (Base) | Mutated Form | Blocked Exceptions |
|---|---|---|
| vowel | t- | None |
| s | ts | Does not mutate before: sc, sf, sm, sp, st |
The following words and grammatical contexts trigger consonant mutations in Irish:
my (possessive, triggers séimhiú)
your (singular, triggers séimhiú)
his (triggers séimhiú)
the (with feminine singular nouns, triggers séimhiú)
past tense marker (triggers séimhiú on verb)
negative particle (triggers séimhiú)
in the (triggers séimhiú except d/t/s)
adjective after feminine singular noun (triggers séimhiú)
on / interrogative particle (triggers séimhiú)
past/conditional copula (triggers séimhiú)
our (triggers urú)
your (plural, triggers urú)
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