Locale Cy 001

Reference data for the Welsh locale — endonym Cymraeg, written in the Latin script, left-to-right (LTR).

Identifiers

• BCP 47 tag: cy-001
• ISO 639-1: cy
• ISO 639-3: cym
• Script: Latn (Latin)
• Region: 001 (World)
• Text direction: ltr — left-to-right (LTR)

Speakers (approximate)

• L1 (native): 562,000
• L2 (additional): 338,000
• L1+L2 (total): 900,000

Regional variants

This is the base/macro locale for Welsh. Region-specific variants in this dataset:

• Locale Cy Gb (Welsh (United Kingdom))

Pluralization

CLDR plural categories for this locale: zero, one, two, few, many, other (6 forms).

• zero — n = 0 (e.g. 0)
• one — n = 1 (e.g. 1)
• two — n = 2 (e.g. 2)
• few — n = 3 (e.g. 3)
• many — n = 6 (e.g. 6)
• other — everything else (e.g. 4, 5, 7~20, 100, …)

See Unicode Messageformat for writing plural messages using these categories.

Translating into this locale

Welsh (Cymraeg) is a Celtic language and an official language of Wales. The Welsh Language Commissioner, the Welsh Government, and Bangor and Cardiff universities produce terminology and style guidance. See Locale Cy Gb.

Translate ideas, not words.

• Welsh is verb-subject-object in its basic order, and in everyday sentences uses an auxiliary bod (to be) plus a verbal noun: Mae'r ffeil wedi'i chadw (is the file after-its saved). Reorder English sentences.
• Welsh text is not the translation of English text; the Welsh Language Standards require equal treatment. Treat both versions as parallel texts that mean the same, and review them together.
• Welsh has no single words for "yes" and "no"; the answer repeats the verb (Ydy, Nac ydy).
• Use Welsh terminology from the Welsh Government's Termcymru terminology portal where it exists.

Grammar that trips translators.

• Initial mutations: soft (cath to gath), nasal (cath to nghath), and aspirate (cath to chath) are triggered by articles, prepositions, numerals, and possessives. Missing mutations are the commonest machine-translation error.
• Two genders (masculine, feminine) that trigger mutations (feminine singular nouns lenite after the article).
• Inflected prepositions (arnaf, ynddo, ohoni) fuse a preposition and a pronoun.
• Numerals: nouns after numerals are singular; numbers use a decimal or traditional vigesimal system. Plural categories in CLDR: zero, one, two, few, many, and other. See Unicode Messageformat.
• Plural nouns have irregular forms (ffeil, ffeiliau).

Register.

• Ti (informal singular) and chi (formal or plural). Public bodies and service text use chi; friends and children use ti. Do not mix. UI commands use the imperative (Cadwch with chi, Cadw with ti) or the verbal noun.
• Welsh Government guidance promotes plain Welsh (Cymraeg clir) and avoids overly formal literary forms in public text.

Orthography and typography.

• Welsh digraphs ch, dd, ff, ng, ll, ph, rh, th are single letters in the alphabet. The circumflex (â ê î ô û ŵ ŷ) marks long vowels and the grave and acute accents appear in some words; keep them.
• Quotation marks ‘…’ or “…”; dates 17 Hydref 2026; pound sterling (£); 24-hour clock.
• In bilingual material the Welsh text is normally presented first or in the first position (left or top), consistent with the Welsh Language Standards.

Common pitfalls

• Missing mutations.
• Translating English word order.
• Dropping circumflexes (ŵ, ŷ).
• Writing the Welsh as a translation of the English instead of a parallel text.
• Relying on machine translation without a native reviewer.

Learn more

• Locale for BCP 47 identifiers, locale-sensitive formatting, pluralization, and text-direction concepts that apply across all locales.
• Unicode Messageformat for writing plural/selection messages correctly for this locale's grammar.
• Welsh Language Commissioner (https://www.welshlanguagecommissioner.wales)
• Welsh Government, Termcymru terminology portal