Grammar & accuracy · Both
Welsh Mutations (Treigladau)
Mutations change the start of a word after certain triggers. Accuracy marks often depend on getting the most common patterns right.
The three mutations (overview)
• **Soft (meddal)** – very common after i, o, am, ar, gan, and feminine nouns after y
• **Nasal (trwynol)** – after yn (meaning “in”) and fy
• **Aspirate (llaes)** – after a, â, tri, chwe (with certain letters)
You do not need every exception for a solid grade – master the high-frequency triggers first.
Study tip
Keep a small personal list of triggers you mix up.
When proofreading, check the word after i / o / yn / fy / y (with feminine nouns).
Worked example
Why does ‘cath’ become ‘gath’ after ‘y’?
Solution: Feminine noun after the article y → soft mutation: y gath.
Practice questions
1. Name the three mutation types.
2. Give one common soft-mutation trigger.