-acht

See also: acht, Acht, ächt, and åcht

Irish

Alternative forms

-eacht (slender variant)
-ocht (following í)

Etymology

From Old Irish -acht (compare Scottish Gaelic -achd).

Suffix

-acht f

Nominal suffix, used to form abstract ideas or nouns roughly corresponding to English -ness, -hood, -ity, or -ure.

Usage notes

This affix forms feminine nouns of the third declension. Abstract nouns do not have plural forms; however, concepts that refer to concrete items do have plurals in -aí.

Declension

Abstract nouns:

Declension of -acht (third declension, no plural)

bare forms
	singular
nominative	-acht
vocative	a -acht
genitive	-achta
dative	-acht

forms with the definite article
	singular
nominative	an -acht
genitive	na -achta
dative	leis an -acht don -acht

Concrete nouns:

Declension of -acht (third declension)

bare forms
	singular	plural
nominative	-acht	-achtaí
vocative	a -acht	a -achtaí
genitive	-achta	-achtaí
dative	-acht	-achtaí

forms with the definite article
	singular	plural
nominative	an -acht	na -achtaí
genitive	na -achta	na -achtaí
dative	leis an -acht don -acht	leis na -achtaí

Derived terms

Irish terms suffixed with -acht

Old Irish

Etymology

From Proto-Celtic *-axtā, suffixal use of Proto-Celtic *axtā.

Suffix

-acht f

-ness, -hood; forms abstract nouns.

Usage notes

After a palatalised consonant, the suffix becomes -echt.

Inflection

Feminine ā-stem
	singular	dual	plural
nominative	-acht^L	-acht^L	-achta^H
vocative	-acht^L	-acht^L	-achta^H
accusative	-acht^N	-acht^L	-achta^H
genitive	-achtae^H	-acht^L	-acht^N
dative	-acht^L	-achtaib	-achtaib

Initial mutations of a following adjective:

^H = triggers aspiration
^L = triggers lenition
^N = triggers nasalization

Derived terms

Old Irish terms suffixed with -acht

Descendants

Irish: -acht
Manx: -aght
Scottish Gaelic: -achd