Numbers – Ordinals: First, second, third

Ordinal numbers denote the position of something in a series, such as first, second or third.

Ordinal numbers are based on the vigesimal system of counting, with the ordinal suffix being added to the first part of the phrase, eg unfed ar ddeg for eleven, not un ar ddegfed. The ordinal abbreviations are not necessarily the same as the ordinal suffixes, eg unfed ar ddeg is abbreviated to 11eg, not 11fed.

There is no decimalised form for ordinal numbers.

After 31st, use either just the number or rhif plus the number, eg rhif pedwardeg tri, forty third.