blynedd / blwydd After Numbers

Years and Age After Numbers

Level 4

After a number, year is blynedd, and after pum and some other numbers it becomes mlynedd: pum mlynedd (five years).

How It Works

Which word?

  • blwyddyn — a year, the year: un flwyddyn, y flwyddyn nesaf
  • blynedd — years, after a number: tair blynedd
  • blwydd — years of age: tair blwydd oed
  • blynyddoedd — years in general: am flynyddoedd (for years)

What happens after each number.

  • dwy → soft: dwy flynedd, dwy flwydd oed (diwrnod is masculine: dau ddiwrnod)
  • tair, pedair, chwe → no change: tair blynedd, pedair blynedd, chwe blynedd, chwe diwrnod
  • pum, saith, wyth, naw → nasal: pum mlynedd, saith mlynedd, wyth mlwydd oed, naw niwrnod
  • deng, deuddeng, pymtheng, deunaw, ugain, can → nasal: deng mlynedd, deuddeng mlynedd, pymtheng mlwydd oed, deunaw mlynedd, ugain mlynedd, can mlynedd

Deg, deuddeg and pymtheg become deng, deuddeng and pymtheng before these words. These forms are becoming less common in speech, but they are still standard.

Age. Blwydd is optional: Mae hi'n bump oed and Mae hi'n bum mlwydd oed both mean She's five. After yn the number softens: pum → bum, deng → ddeng. See saying your age.

Only these words. Other nouns don't take nasal mutation after numbers: pum munud, deg punt. See nasal mutation and traditional numbers.

Examples (6)

  1. Dw i'n byw yma ers pum mlynedd.

    I've lived here for five years.

    Blynedd becomes mlynedd after pum.

  2. Mae ein ci ni'n saith mlwydd oed.

    Our dog is seven years old.

    Blwydd becomes mlwydd after saith.

  3. Bydd hi i ffwrdd am ddeng niwrnod.

    She'll be away for ten days.

    Diwrnod becomes niwrnod after deng, and am softens deng to ddeng.

  4. Aethon nhw i Awstralia ddwy flynedd yn ôl.

    They went to Australia two years ago.

    After dwy, blynedd softens to flynedd.

  5. Mae'r capel yn gan mlwydd oed.

    The chapel is a hundred years old.

    Can softens to gan after yn, and blwydd becomes mlwydd after it.

  6. Arhoson ni yno am naw niwrnod.

    We stayed there for nine days.

Common Mistakes

  • Forgetting the nasal mutation after pum.

    pum blynedd
    pum mlynedd

    After pum, blynedd takes nasal mutation: b becomes m.

  • Using blwyddyn after a number.

    pum blwyddyn
    pum mlynedd

    After a number, use the special form blynedd, not blwyddyn.

How It Connects

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

blynedd / blwydd After NumbersLevel 4Years and Age After Numbers

Learn This First

Blynedd and blwydd take nasal mutation after certain numbers.

Words in This Pattern

blyneddblwydddengdeuddengpumwythnawdeunawugaincan