-rwydd / -der / -wch / -aeth

Abstract Noun Suffixes

Level 5

Add an ending to a describing word to make a word for the quality: hapus (happy) → hapusrwydd (happiness), tawel (quiet) → tawelwch (quiet, silence).

How It Works

What an abstract noun is. It names an idea or quality, not a thing you can touch: happiness, depth, beauty, music. English uses endings like -ness and -ity; Welsh has its own set.

  • -rwydd: hapus → hapusrwydd (happiness), sicr → sicrwydd (certainty), caredig → caredigrwydd (kindness), parod → parodrwydd (readiness)
  • -der (-ter after some sounds, as in anhawster, difficulty): dwfn → dyfnder (depth), dewr → dewrder (bravery), prin → prinder (shortage), cyflym → cyflymder (speed)
  • -wch: prydferth → prydferthwch (beauty), tawel → tawelwch (quiet, silence), tywyll → tywyllwch (darkness), teg → tegwch (fairness)
  • -aeth: cerdd → cerddoriaeth (music), aelod → aelodaeth (membership), meddyg → meddygaeth (medicine), gwybod → gwybodaeth (knowledge, information)

Changes to the stem. Adding a syllable moves the stress, and the vowel can change, as it does in some plurals: dwfn gives dyfnder. Some words also add a linking sound, like the -i- in cerddoriaeth. Learn these words whole.

Gender. Most nouns in -aeth are feminine, so they soften after y: y wybodaeth (the information), y gerddoriaeth (the music). Gwasanaeth (service) and hiraeth (longing) are common masculine exceptions. See Soft Mutation After Y.

Other endings. You will also meet -deb (ffyddlondeb, faithfulness), -edd (gwirionedd, truth) and -iant (llwyddiant, success).

Examples (6)

  1. Dw i'n dymuno pob hapusrwydd i chi.

    I wish you every happiness.

    Hapus (happy) + -rwydd.

  2. Beth ydy dyfnder y llyn?

    How deep is the lake?

    Dwfn (deep) + -der; the vowel changes to y.

  3. Mae prydferthwch yr ardal yn denu ymwelwyr.

    The beauty of the area attracts visitors.

    Prydferth (beautiful) + -wch.

  4. Mae hi'n astudio cerddoriaeth yn y brifysgol.

    She studies music at university.

    Cerdd (song, poem) + -oriaeth.

  5. Diolch am eich caredigrwydd.

    Thank you for your kindness.

  6. Mae angen mwy o wybodaeth arnon ni.

    We need more information.

    Gwybodaeth (from gwybod, know) softens after o.

Common Mistakes

  • Forgetting that most -aeth nouns are feminine.

    Diolch am y gwybodaeth.
    Diolch am y wybodaeth.

    Gwybodaeth is feminine, so it softens after the article: y wybodaeth.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

-rwydd / -der / -wch / -aethLevel 5Abstract Noun Suffixes

Learn This First

Abstract nouns are formed with suffixes that shift stress.

Words in This Pattern

-rwydd-der-wch-aeth