The traditional counting system used in the

Welsh language Welsh ( or ) is a Celtic language of the Brittonic subgroup that is native to the Welsh people. Welsh is spoken natively in Wales, by some in England, and in Y Wladfa (the Welsh colony in Chubut Province, Argentina). Historically, it h ...

vigesimal vigesimal () or base-20 (base-score) numeral system is based on twenty (in the same way in which the decimal numeral system is based on ten). '' Vigesimal'' is derived from the Latin adjective '' vicesimus'', meaning 'twentieth'. Places In a ...

, i.e. based on twenties where numbers from 11–14 are "''x'' on ten", 16–19 are "''x'' on fifteen" (though 18 is more usually "two nines"); numbers from 21–39 are "1–19 on twenty", 40 is "two twenty", 60 is "three twenty", etc. There is also a decimal counting system, where numbers are "''x'' ten ''y''" unit(s), e.g. thirty-five in decimal is ' (three ten five) while in vigesimal it is ' (fifteen – itself "five-ten" – on twenty).

Numerals

Variation in form

There is some syntactically and phonologically triggered variation in the form of numerals. There are, for example, masculine and feminine forms of the numbers "two" (' and '), "three" (' and ') and "four" (' and '), which must agree with the

grammatical gender In linguistics, grammatical gender system is a specific form of noun class system, where nouns are assigned with gender categories that are often not related to their real-world qualities. In languages with grammatical gender, most or all noun ...

of the objects being counted. The numerals for "five", "six" and "hundred" (', ' and ') also have reduced forms (', ', ') when they precede the object they are counting. The words for "ten", "twelve", and "fifteen" (', ', ') have the alternative forms ', ', ' used before nasals (which may be the result of mutation) and, occasionally, vowels; these forms are becoming less common. Numerals change as expected according to normal rules of

consonant mutation Consonant mutation is change in a consonant in a word according to its morphological or syntactic environment. Mutation occurs in languages around the world. A prototypical example of consonant mutation is the initial consonant mutation of all ...

; some also trigger mutation in some following words (see below for details).

Use of the decimal system

The decimal system is widely used, but is rather uncommon for dates and ages. Larger numbers, however, tend to be expressed in this system e.g. 1,965 '. In referring to years, on the other hand, the number of thousands is stated, followed by the individual digits, e.g. 1965 '. This system appears to have broken down for years after 2000, e.g. whereas 1905 is ', 2005 is '. The Welsh decimal counting system was devised by 19th-century

Patagonian Welsh Patagonian Welsh (Welsh language, Welsh: ''Cymraeg y Wladfa'') is a variety of the Welsh language spoken in Y Wladfa, the Welsh settlement in Patagonia, Chubut Province, Argentina. The decimal numeral system used in Modern Welsh originated in ...

businessmen in Argentina for accountancy purposes. It was recommended to teachers for use in the first Welsh language schools in Patagonia by

Richard Jones Berwyn Richard Jones Berwyn (October 1837 – 25 December 1917) was an early Welsh colonist in Patagonia. Early life Richard Jones was born in October 1837 in Glyndyfrdwy Glyndyfrdwy (), or sometimes Glyn Dyfrdwy, is a village in the modern county ...

in a book published in 1878. The system was later adopted in Wales in the late 1940s with the beginning of

Welsh-medium education Education delivered through the medium of the Welsh language is known as Welsh-medium education (). Welsh-medium education should be distinguished from the teaching of the Welsh language itself as an academic subject. 16% of pupils in Wales atte ...

Use with nouns

The singular form of the noun is used with numbers, but for larger numbers an alternative form is permitted, where ' ("of") with the plural noun follows the number. Except where using this plural form, the noun is placed directly after the number but before any parts of the number that are added using ' ("on") in the traditional system. Nouns are also mutated following many numbers. ' triggers the

soft mutation In linguistics, lenition is a sound change that alters consonants, making them more sonorous. The word ''lenition'' itself means "softening" or "weakening" (from Latin 'weak'). Lenition can happen both synchronically (within a language at ...

(') of feminine nouns, other than those beginning with "ll" and "rh", but not masculine nouns. ' and ' both trigger the soft mutation (''ll'' and ''rh'' included). ' (but not ') and ' trigger the aspirate mutation. Several higher numbers (', ', ', ', ', and ') trigger the nasal mutation when used with ' ("year(s)"). The part of the number immediately preceding the noun will determine any mutation of the noun. In the plural form with ', the soft mutation is used as is normal after '. The following example illustrates several of these points:

Notes

{{Welsh linguistics Welsh language Numerals