# -ach
## Chuukese
### Suffix

-ach
* (added to possessive nouns) our (inclusive)

#### Related terms
## Irish
### Pronunciation

* (Munster, Connacht) IPA: /əx/
* (Ulster) IPA: /ax/, /ah/, /a/

### Etymology 1

From Old Irish -ach, from Proto-Celtic *-ākos, from Proto-Indo-European *-eh₂kos, *-eh₂ḱos, from a-stem suffix *-eh₂ + adjectival suffix *-kos, *-ḱos; compare Welsh -og. Doublet of -óg.

#### Alternative forms

* -each (slender form)

#### Suffix

-ach m
* Forms nouns from other nouns and adjectives with the sense of ‘person or thing connected or involved with, belonging to, having’.
    ‎Éire (“Ireland”) + ‎-ach → ‎Éireannach (“Irish (person)”)
    ‎Sasana (“England”) + ‎-ach → ‎Sasanach (“English (person)”)
* Forms adjectives from other nouns and adjectives with the sense of ‘connected or involved with, belonging to, having’.
    ‎bunús (“basis”) + ‎-ach → ‎bunúsach (“basic”)
    ‎fearg (“anger”) + ‎-ach → ‎feargach (“angry”)
    ‎Éire (“Ireland”) + ‎-ach → ‎Éireannach (“Irish”)
    ‎Sasana (“England”) + ‎-ach → ‎Sasanach (“English”)

##### Declension

For nouns:
bare forms
case
singular
plural
nominative
-ach
-aigh
vocative
a -aigh
a -acha
genitive
-aigh
-ach
dative
-ach
-aigh
forms with the definite article
case
singular
plural
nominative
an -ach
na -aigh
genitive
an -aigh
na -ach
dative
leis an -ach don -ach
leis na -aigh :
For adjectives:

##### Derived terms

* -achán
* -achas

### Etymology 2

From Old Irish -ach, from Proto-Celtic *-Vkos (V standing for any vowel), the genitive singular ending of certain nouns ending in *-Vxs.

#### Suffix

-ach
* forms the genitive singular of some fifth-declension nouns

## Middle Irish
### Etymology

From Old Irish -ach, from Proto-Celtic *-ākos, from Proto-Indo-European *-eh₂kos, *-eh₂ḱos, from a-stem suffix *-eh₂- + adjectival suffix *-kos, *-ḱos. Doublet of -óc.

### Pronunciation

* IPA: /əx/

### Suffix

-ach
* Forms adjectives meaning "related to, having, characterised by, prone to".
* Forms nouns meaning "person or thing connected or involved with, belonging to, having".

#### Usage notes

After a palatalised consonant, the suffix becomes -ech.

#### Descendants

* Irish: -ach
* Manx: -agh
* Scottish Gaelic: -ach

## Middle Welsh
### Etymology

From Proto-Brythonic *-ox, with the vowel altered by influence from -af.

### Suffix

-ach
* forms a comparative adjective

#### Derived terms
## Old Irish
### Etymology

From Proto-Celtic *-ākos, from Proto-Indo-European *-eh₂kos, *-eh₂ḱos, from a-stem suffix *-eh₂- + adjectival suffix *-kos, *-ḱos. Doublet of -óc.
Compare Latin -ācus, -icus.

### Pronunciation

* IPA: /ax/

### Suffix

-ach
* Forms adjectives meaning "related to, having, characterised by, prone to".
* Forms nouns meaning "person or thing connected or involved with, belonging to, having".

#### Usage notes

After a palatalised consonant, the suffix becomes -ech.

#### Inflection

Adjective:
o/ā-stem :
| Singular | Masculine | Feminine | Neuter |
| Nominative | -ach | -ach | -ach |
| Vocative | -aig* -ach** | -ach | -ach |
| Accusative | -ach | -aig | -ach |
| Genitive | -aig | -aige | -aig |
| Dative | -uch | -aig | -uch |
| Plural | Masculine | Feminine/neuter | Feminine/neuter |
| Nominative | -aig | -acha | -acha |
| Vocative | -achu -acha† | -acha | -acha |
| Accusative | -achu -acha† | -acha | -acha |
| Genitive | -ach | -ach | -ach |
| Dative | -achaib | -achaib | -achaib |
| Notes | *modifying a noun whose vocative is different from its nominative **modifying a noun whose vocative is identical to its nominative † not when substantivized | *modifying a noun whose vocative is different from its nominative **modifying a noun whose vocative is identical to its nominative † not when substantivized | *modifying a noun whose vocative is different from its nominative **modifying a noun whose vocative is identical to its nominative † not when substantivized |
Noun:
* $^H$ = triggers aspiration
* $^L$ = triggers lenition
* $^N$ = triggers nasalization

#### Descendants

* Middle Irish: -ach
** Irish: -ach
** Manx: -agh
** Scottish Gaelic: -ach

### Further reading

* Thurneysen, Rudolf (1940) D. A. Binchy and Osborn Bergin, transl., A Grammar of Old Irish, Dublin Institute for Advanced Studies, →ISBN, § 347; reprinted 2017

## Scottish Gaelic
### Alternative forms

* -each (slender form)

### Etymology

From Old Irish -ach, from Proto-Celtic *-ākos, from Proto-Indo-European *-eh₂kos, *-eh₂ḱos, from a-stem suffix *-eh₂- + adjectival suffix *-kos, *-ḱos; compare Welsh -og. Doublet of -ag.

### Pronunciation

* IPA: [ax]

### Suffix

-ach (plural -aich or -aichean)
* Forming nouns from nouns and adjectives with the sense of ‘person or thing connected or involved with, belonging to, having’.

#### Derived terms
## Welsh
### Pronunciation

* IPA: /aχ/

### Etymology 1

From Middle Welsh -ach, from Proto-Brythonic *-ox, with the vowel altered by influence from -af.

#### Suffix

-ach
* Forms a comparative adjective.
    ‎ifanc (“young”) + ‎-ach → ‎ifancach (“younger”)
    ‎pwysig (“important”) + ‎-ach → ‎pwysicach (“more important”)
    ‎tlawd (“poor”) + ‎-ach → ‎tlotach (“poorer”)

##### Usage notes

Triggers fortition of the final consonant of the adjectival stem.

##### Derived terms
### Etymology 2
#### Alternative forms

* -iach

#### Suffix

-ach
* pejorative suffix
    ‎cor (“dwarf”) + ‎-ach → ‎corrach (“dwarf, gnome”)
    ‎cawl (“soup”) + ‎-ach → ‎cawlach (“mess, hotchpotch”)
    ‎dillad (“clothes”) + ‎-ach → ‎dilladach (“old clothes, worthless clothing”)

##### Derived terms
### Etymology 3
#### Suffix

-ach f
* suffix forming abstract nouns and some verbnouns
    ‎cyfrin (“privy, cryptic”) + ‎-ach → ‎cyfrinach (“secret”)
    ‎cyfaill (“friend”) + ‎-ach → ‎cyfeillach (“fellowship, companionship”)
    ‎clinc (“clink, tinkle”) + ‎tarddu (“emerge, erupt”) + ‎-ach → ‎clindarddarch (“crackling; to crackle”)

##### Derived terms
### References

R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke et al., editors (1950–present), “-ach”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies