Aspirate Mutation in Welsh

In Brief

The Welsh aspirate mutation (treiglad llaes) changes only three initial consonants: p → ph, t → th, and c → ch. At beginner level, learn these changes after ei “her,” â “with,” tri “three,” and chwe “six”: ci “dog” becomes ei chi “her dog,” for example. Words beginning with other letters do not undergo this mutation.

Overview

A mutation is a regular change to the beginning of a Welsh word. It does not create a new word, and it usually does not change the word’s basic meaning. Instead, a preceding word or grammatical pattern triggers a different initial sound. English does not have a close equivalent, so an English-speaking learner must get used to treating the beginning of a word as something that can change.

The aspirate mutation is one of the smallest Welsh mutation patterns. It affects only words whose unchanged, or radical, form begins with p, t, or c. The name “aspirate” is traditional grammatical terminology; the useful fact is that each of the three resulting spellings represents a different sound. This pattern appears early, at A1, because it is needed in ordinary phrases about possession, accompaniment, and numbers.

The beginner task is manageable: memorise three sound changes and four high-value triggers. You do not need to mutate every word after these triggers—only a word beginning with p, t, or c can show the aspirate mutation.

How It Works

The three changes

Radical form	Mutated form	Approximate sound	Example
p	ph	f as in fine	pen → ei phen (“head” → “her head”)
t	th	th as in thin, not this	tad → ei thad (“father” → “her father”)
c	ch	the sound in Scottish loch	ci → ei chi (“dog” → “her dog”)

In Welsh spelling, ph, th, and ch are digraphs (pairs of letters representing one consonant sound). Do not pronounce ph as two sounds, and do not pronounce Welsh ch like English ch in chair.

The mutation applies to the beginning of the next relevant word:

• plant → â phlant (“with children”)
• te → â the (“with tea”)
• cyllell → â chyllell (“with a knife”)

If the next word begins with another consonant, there is no visible aspirate mutation: ei brawd hi (“her brother”), â Megan (“with Megan”).

After ei: “her”

The possessive word ei means “his,” “her,” or “its,” depending on the mutation and the wider sentence. When it means “her,” it triggers the aspirate mutation:

Radical noun	With ei “her”	Meaning
pen	ei phen	her head
tad	ei thad	her father
cath	ei chath	her cat
brawd	ei brawd	her brother; no change is possible here

Welsh often adds hi after the possessed noun, especially when clarity or emphasis is useful: ei chath hi, literally the Welsh pattern for “her cat.” The final hi does not remove the mutation.

This mutation can distinguish two phrases that look almost identical in English:

• ei gi — his dog (soft mutation: ci → gi)
• ei chi — her dog (aspirate mutation: ci → chi)

That contrast is an excellent reason to learn the mutation rather than treating it as optional spelling decoration.

After â: “with”

The preposition (a short relationship word) â means “with” and triggers the aspirate mutation:

• â phlant — with children
• â the — with tea
• â chyllell — with a knife
• â phump — with five

The circumflex matters: â means “with,” while a without the accent commonly means “and.” A frequent everyday expression is Paid â phoeni! (“Don’t worry!”), where poeni becomes phoeni.

After tri: “three”

Tri is used with masculine nouns (nouns belonging to the masculine grammatical class) and triggers the aspirate mutation:

• tri phlentyn — three children
• tri thŷ — three houses
• tri chi — three dogs

Welsh normally uses a singular noun after a number, even when English uses a plural: tri chi, literally “three dog,” not tri cŵn. The corresponding feminine form of “three” is tair, so do not automatically put tri before every noun.

After chwe: “six”

Chwe also triggers the aspirate mutation before a following noun:

• chwe phunt — six pounds
• chwe thocyn — six tickets
• chwe cheffyl — six horses

Again, the noun is normally singular after the number: chwe cheffyl, not the ordinary plural chwe ceffylau.

A quick decision process

When you build a phrase, ask two questions:

1. Is the preceding word one of the triggers you have learned: ei “her,” â, tri, or chwe?
2. Does the next word begin with p, t, or c?

If both answers are yes, use ph, th, or ch. If the answer to the second question is no, leave the initial consonant unchanged.

Examples in Context

Welsh	English	Note
Mae ei chi yn yr ardd.	Her dog is in the garden.	ci → chi after ei “her”
Dyma ei thad hi.	Here is her father.	tad → thad; final hi reinforces “her”
Mae ei phlant hi yn yr ysgol.	Her children are at school.	plant → phlant
Mae ei brawd hi yma.	Her brother is here.	No change: brawd does not begin with p, t, or c
Dw i’n mynd â phlant i’r parc.	I’m taking children to the park.	plant → phlant after â
Ga i de â thipyn o laeth?	May I have tea with a little milk?	tipyn → thipyn after â
Torrwch y bara â chyllell finiog.	Cut the bread with a sharp knife.	cyllell → chyllell
Paid â phoeni!	Don’t worry!	Common expression; poeni → phoeni
Mae’r rhes yn dechrau â phump.	The sequence starts with five.	pump → phump
Mae tri phlentyn yn chwarae tu allan.	Three children are playing outside.	plentyn → phlentyn; singular noun after tri
Gwelais i dri chi ar y traeth.	I saw three dogs on the beach.	ci → chi after tri
Mae ganddyn nhw dri thocyn.	They have three tickets.	tocyn → thocyn
Prynon ni chwe phunt o afalau.	We bought six pounds of apples.	punt → phunt after chwe
Mae chwe cheffyl yn y cae.	There are six horses in the field.	ceffyl → cheffyl; singular noun after the number
Prynais i chwe thocyn i’r cyngerdd.	I bought six tickets for the concert.	tocyn → thocyn after chwe

Common Mistakes

1. Using the soft mutation for “her”

• Wrong: ei gi hi for “her dog”
• Right: ei chi hi
• Why: ci → gi is the soft mutation and normally signals “his dog” after ei. For “her,” c takes the aspirate form ch.

2. Mutating letters outside the three-letter set

• Wrong: changing brawd in ei brawd hi as though every noun must change
• Right: ei brawd hi
• Why: The aspirate mutation acts only on initial p, t, and c. Initial b, d, g, m, ll, rh, and other consonants do not change under this pattern.

3. Writing the trigger but keeping the radical consonant

• Wrong: â plant, tri ci, chwe tocyn
• Right: â phlant, tri chi, chwe thocyn
• Why: In standard Welsh, these triggers require the aspirate forms ph, ch, and th.

4. Pronouncing the mutated spelling as if it were English

• Wrong: pronouncing chath with the English sound in chat, or thad with the voiced sound in this
• Right: use the loch sound in chath and the thin sound in thad
• Why: Welsh spelling has its own stable sound values. The mutation changes pronunciation as well as spelling.

5. Using an ordinary plural after a number

• Wrong: tri cŵn or chwe ceffylau in the basic counting pattern
• Right: tri chi, chwe cheffyl
• Why: A noun directly following a Welsh cardinal number is normally singular. Apply the mutation to that singular form.

6. Confusing a and â

• Wrong: mynd a phlant when you mean “go with children”
• Right: mynd â phlant
• Why: The circumflex distinguishes the preposition â “with” from a “and” in standard writing.

Usage Notes

Mutation belongs to both written and spoken Welsh. In careful speech, the changed sound is audible; it is not merely a spelling convention. In rapid or strongly colloquial speech, mutation use can vary by speaker and region, but learners should use the standard pattern in writing and practise hearing it in speech.

With possessives, the following pronoun often makes the meaning especially clear: ei phen hi (“her head”), compared with ei ben e (“his head,” in a common southern form). You will also encounter northern o for “him.” These regional pronouns do not change the central rule: feminine “her” triggers the aspirate mutation where p, t, or c allows it.

The number forms deserve special attention. Tri goes with masculine nouns, while tair is the feminine form. A dictionary that marks noun gender helps you choose correctly. Chwe is used regardless of noun gender. In both patterns, standard Welsh usually places the singular noun directly after the number.

Beyond the Basics: Related Aspirate Patterns

You do not need to master this section at A1, but it explains forms you will soon see in natural Welsh.

The conjunction a “and” can also cause the aspirate mutation: bara a chaws (“bread and cheese”), from caws. This is a separate use from â “with,” although both words are associated with the same mutation. In ordinary text, context and the circumflex show which one is intended.

When ei means “her” and the following word begins with a vowel, Welsh often adds h: ei henw hi (“her name”) and ei hysgol hi (“her school”). This is usually called h-prothesis—adding an h at the front—rather than one of the three consonant changes of the aspirate mutation. It belongs with the same possessive pattern and is useful to recognise.

The possessive ei can also refer to an inanimate possessor translated as “its.” Welsh nouns have grammatical gender, so a feminine possessor can trigger the same pattern. In more connected structures, ei may appear in a shortened form, as in y gadair a’i choes (“the chair and its leg”). Here the feminine noun cadair determines the possessive pattern, and coes appears as choes.

Finally, mutation is grammatical, not a permanent replacement of the dictionary form. Look up phlentyn under plentyn, thocyn under tocyn, and chyllell under cyllell. Learning to reverse ph → p, th → t, and ch → c is an important reading and dictionary skill.

Practice Tips

1. Make three sound columns. Write five familiar words under each radical initial—p, t, and c—then say each pair aloud: pen/phen, tad/thad, ci/chi. Concentrate on the changed sound, not only the spelling.
2. Rotate the four triggers. Take one suitable noun and build short phrases with ei, â, tri, or chwe. Not every noun fits every meaning, but the repetition makes the trigger-and-change sequence automatic.
3. Read mutations backwards. Whenever you meet a word beginning with ph, th, or ch, ask whether its radical form might begin with p, t, or c. Then check what comes immediately before it. This trains you to recognise both vocabulary and grammar in real sentences.

Related Concepts

• Prerequisite: Soft Mutation — compare its larger set of consonant changes and the important contrast between ei gi “his dog” and ei chi “her dog.”