Literary Welsh morphology

The morphology of the Welsh language shows many characteristics perhaps unfamiliar to speakers of English or continental European languages like French or German, but has much in common with the other modern Insular Celtic languages: Irish, Scottish Gaelic, Manx, Cornish, and Breton. Welsh is a moderately inflected language. Verbs conjugate for person, tense and mood with affirmative, interrogative and negative conjugations of some verbs. A majority of prepositions inflect for person and number. There are few case inflections in Literary Welsh, being confined to certain pronouns.

Modern Welsh can be written in two varieties – Colloquial Welsh or Literary Welsh. The grammar described on this article is for Literary Welsh.

Initial consonant mutation is a phenomenon common to all Insular Celtic languages (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 depending on grammatical context (such as when the grammatical object directly follows the grammatical subject), when preceded by certain words, e.g. i, yn, and a or when the normal word order of a sentence is changed, e.g. Y mae tŷ gennyf, Y mae gennyf dŷ "I have a house".

Welsh has three mutations across four paradigms: the soft mutation (Welsh: treiglad meddal), the nasal mutation (Welsh: treiglad trwynol), and the aspirate (or spirant) mutation (Welsh: treiglad llaes); and the mixed mutation (Welsh: treiglad cymysg) where the aspirate mutation is applied where possible, else the soft mutation is applied. These are represented in writing, as shown in the table below along with their corresponding IPA symbols.

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).

* The soft mutation for g is the simple deletion of the initial sound. For example, gardd "garden" becomes yr ardd "the garden". But this can behave as a consonant under certain circumstances, e.g. "gellir" (one can) becomes "ni ellir" (one cannot) not "*nid ellir". This however also stands alongside gardd ('a garden'), but yr ardd ('the garden') not *y ardd.

The soft mutation (Welsh: treiglad meddal) is, by far, the most common mutation in Welsh. When words undergo soft mutation, the general pattern is that voiceless plosives become voiced plosives, voiced plosives become voiced fricatives, and voiceless liquids becomes voiced. The full list is shown in the above table.