100 to 1,000,000

Irish uses a clear, component-based system for forming large numbers. Once you know the words for “hundred” (céad), “thousand” (míle), and “million” (milliún), you can construct larger values by combining them with the numbers from 1-99. This page covers the three main types of numbers: abstract (maoluimhreacha), cardinal (bunuimhreacha), and ordinal (orduimhreacha).

Abstract Numbers (Maoluimhreacha)

Abstract numbers, or maoluimhreacha, are used for counting without referring to a specific noun, like saying “one, two, three…” or reading out a year. The structure for numbers over 100 often uses a to connect the parts.

• céad a haon - one hundred and one
• míle naoi gcéad seasca a hocht - one thousand, nine hundred and sixty-eight (the year 1968)

Cardinal Numbers (Bunuimhreacha)

Cardinal numbers, or bunuimhreacha, are used to count nouns like people or objects. The structure is slightly different from abstract numbers, often using is (“and”) to connect the number to the noun.

• céad bád - one hundred boats
• céad is dhá bhád - one hundred and two boats

Grammar Rules

1. Noun Form: After céad, míle, and milliún, the noun that follows stays in the singular. For example, céad bád (100 boats), not *céad báid.
2. Connecting with is: For numbers like 101, 102, etc., the word is (“and”) is used before the noun. For example, céad is bád means “101 boats”.
3. Mutations: The final digit of the number determines the mutation of the following noun, following the standard rules for numbers 1-19.
   • Lenition: after dhá (two). e.g., céad is dhá bhád (102 boats).
   • Eclipsis: after seacht, ocht, naoi, deich (7, 8, 9, 10). e.g., céad is seacht mbád (107 boats).

Examples

Ordinal Numbers (Orduimhreacha)

Ordinal numbers indicate position in a sequence (e.g., “first”, “second”, “hundredth”). In Irish, they are formed by adding a suffix, usually -ú, to the cardinal number and are preceded by the definite article an.

• an chéadú bád - the 100th boat
• an míliú bád - the 1000th boat

Grammar Rules

1. The Suffix -ú: The ending -ú is added to the number to make it ordinal. For numbers ending in a vowel, this may be adjusted, for example, fiche becomes fichiú.
2. The Definite Article an: Ordinal numbers are almost always used with an. This causes lenition where applicable (e.g., céad -> an chéadú) and adds a t-prefix before a vowel (e.g., ocht -> an t-ochtú).
3. Compound Ordinals: For numbers like 101st, the structure is an (larger number) is (smaller ordinal). For example, an céad is aonú bád (the 101st boat).

Examples

Very Large Numbers

The system extends logically for even larger numbers.