Colloquial Welsh Morphology - Initial Consonant Mutation

Initial Consonant Mutation

Initial consonant mutation is a phenomenon common to all Insular Celtic languages, although there is no evidence of it in the ancient Continental Celtic languages of the early first millennium. The first consonant of a word in Welsh may change when preceded by certain words (e.g. i, yn, and a), or because of some other grammatical context (such as when the grammatical object directly follows the grammatical subject). Welsh has three mutations: the soft mutation, the nasal mutation, and the aspirate mutation. These are also represented in writing:

Radical	Soft	Nasal	Aspirate
p	b	mh	ph
t	d	nh	th
c	g	ngh	ch
b	f	m
d	dd	n
g	∅*	ng
m	f
ll	l
rh	r

*Soft mutation causes initial /g/ to be deleted. For example, gardd "garden" becomes yr ardd "the garden".

A blank cell indicates no change.

For example, the word for "stone" is carreg, but "the stone" is y garreg (soft mutation), "my stone" is fy ngharreg (nasal mutation) and "her stone" is ei charreg (aspirate mutation). These examples represent usage in the standard language; there is some regional and idiolectal variation in colloquial usage. In particular, the soft mutation is often used where nasal or aspirate mutation might be expected on the basis of these examples.

Mutation is not triggered by the form of the preceding word; the meaning and grammatical function of the word are also relevant. For example, while yn meaning "in" triggers nasal mutation, homonyms of yn do not. For example:

• In the sentence Mae plastig yn nhrwyn Siaco ("There is plastic in Siaco's nose") trwyn has undergone nasal mutation.
• In the sentence Mae trwyn Siaco yn blastig ("Siaco's nose is plastic" ) plastig has undergone soft mutation, not nasal mutation.
• In the sentence Mae trwyn Siaco yn cynnwys plastig ("Siaco's nose contains plastic") cynnwys is not mutated.