The phonetic values of the above graphemes has been discussed under the section “sound changes”.
As regards to “s-“ before a consonant, it is dropped, and marked in writing with an apostrophe. In the spoken language, the appearance of a radical in a mutational context indicates the elision of “s-”, therefore indicating the mutation of “s-“.
The various mutations of the modern Celtic languages are categorised according to the phonetic processes which occur, e.g. softening, hardening, nasalisation etc. All of the modern Celtic languages have different kinds and combinations of mutations, although there are deep fundamental resemblances among all of them. The mutations proposed for the modern Gaulish language consist of a combination of phonetic processes, mostly voicing and spirantisation (see above). Therefore, it is easiest to describe this mutation as a “mixed mutation”. However, its description is irrelevant, as there is only one change for each sound.
Contexts for mutation
The contexts for mutation have become apparent throughout this document. It is posited that mutation has become established as a system for assisting with the conveying of grammatical meaning in the wake of the loss of case endings and therefore meaning, as discussed previously. As such, they represent a simple switch from marking the end of words for meaning to marking the start of words for meaning. This position is supported by Isaac (2007) who argues that VSO languages have a greater innate tendency to modify words word initially than word finally.
There are two kinds of contexts for mutation: contact mutation and grammatical mutation. The contact mutation category is the largest one. In contact mutation, a mutation is triggered by a lexeme immediately preceding the word affected. In grammatical mutation, a mutation is bestowed because of a grammatical condition or requirement, which may or may not be caused by a lexeme immediately preceding the word affected.
Contact mutations do not necessarily convey grammatical meaning in themselves; instead they usually assist in the marking of such meaning. However, such meaning would not be apparent in the absence of the lexemes triggering the mutation. As such, it can be said that a large part of the mutations featured in modern Gaulish are phonetic mutations rather than grammatical mutations. This situation is similar to the one prevailing in modern Breton, Welsh and Cornish, where some mutations occur for no apparent reason and carry no apparent grammatical meaning.
Contact mutations
1) after preverbal particles
The following preverbal particles cause mutation: ré, en, a, né, a
ré: past tense marker > cana mi: I sing
ré gan mi: I sang
en: ongoing tense marker > delgha mi: I hold
esi mi en dhelghe: I am holding
a: intentional form marker > depri: to eat
gwéla mi ái a dhepri: I want to go to eat
né: negation marker > gara mi: I call
né ghara mi: I don’t call
a: interrogative marker > gara ti: you call
a ghara ti: do you call?
2) after adverbial particles
The following adverbial particles cause mutation: in, ré, ró, ma
in: adverbial adjective marker > tech: beautiful
in dech: beautifully
ré: intensive marker > már: big
ré wár: very big
ró: excessive marker > ró wár: too big
ma: conditional marker > gwéla mi: I want
ma chwéla mi: if I want
3) after question words
Normally question words are followed by the interrogative particle “a”, which causes mutation on the following word, and is not in itself susceptible to mutation. However, in some cases a question word may be directly followed by a different word, which will then undergo mutation; this only happens if the phrase is used as a question:
pé: what, which
cun: dog
pé gun: which dog?
caman: road, way
pé gaman: which road, which way?
ponch ré hái mi a gáma: when I went to walk > here “ponch” is not used as a question word, so it does not
cause mutation
4) after prepositions
All prepositions cause mutation:
gwer: on, at
mór: sea
gwer wór: at sea (“on [the] sea”)
gwó: under
pren: tree
gwó bren: under a tree
can: with
caran: friend
can garan: with a friend
Grammatical mutations
1) feminine nouns after the article
Feminine nouns both singular and plural mutate when preceded by the article “in”. Thus the gender of nouns is effectively marked by the initial consonant mutation. This is not a contact mutation, because the article does not trigger mutation in masculine nouns.
e.g.: ben: woman
in: the
in ven: the woman
mná: women
in wná: the women
brí: hill
in vrí: the hill
in vríé: the hills
grá: sand
in ghrá: the sand
in ghráé: the sands
2. adjectives qualifying feminine nouns
Adjectives qualifying feminine nouns, whether it be one or several, are marked by mutations:
ben: a woman
tech: beautiful
ben dech: a beautiful woman
brí: a hill
ardhu: high
brí hardhu: a high hill
grá: sand
gwin: white
grá chwin: white sand
grá chwin dech: beautiful white sand
3. after possessive pronouns
Words following possessive pronouns regularly undergo mutation. As this mutation is triggered by the presence of the possessive pronouns, it could be said that this is straightforward contact mutation. However, these mutations differ from contact mutations in two ways:
a) the mutations serve to mark the distinction between the 3rd pers. singular masculine and
feminine, and between the 2nd and the 3rd person plural:
e.g.: cun: dog
mó gun: my dog nó gun: our dog
tó gun: your dog só cun: your (pl.) dog – no ICM
ó gun: his dog – ICM só gun: their dog – ICM
ó cun: her dog – no ICM
b) the mutations are transferred to any words preceding the noun that is
possessed, but also across them to the possessed noun, even though it is no longer in
contact with the mutation trigger:
e.g.: cun: dog
pethr: four
mó bethr gun: my four dogs
Unmutatable words
Some words cannot be mutated, and also block mutation from taking place. These are:
1. the article “in”
The article blocks a contact mutation, and does not mutate itself:
e.g.: pen: head
gwer: on
gwer ben: on a head
gwer in pen: on the head
2. the possessive pronouns
While the possessive pronouns cause mutations (see above), they are not mutatable themselves:
e.g.: pen: head
mó: my
gwer: on
gwer mó ben: on my head
Additional words that do not mutate are the adverbs “né” (not) and “ma” (if). However, contexts that could potentially lead to their mutation are rare. As a broad general rule, those words that do not mutate are those words that cause mutation. Exceptions are the preverbal particles “ré”and “ró”, which do mutate.
Summary of mutation contexts
In summary, mutation is caused by:
1. pre-verbal particles
2. adverbial particles
3. question words if used as such
4. prepositions
5. possessive pronouns
6. the article before feminine nouns
7. adjectives qualifying feminine nouns