Old Irish class A I verbs (Strachan's B1, McCone's W1) are derived from Proto-Celtic verbs ending in *-āti, which are derived from Proto-Indo-European verbs ending in *-eh₂yéti and correspond to the Latin first conjugation, Ancient Greek verbs in -άω (-áō), and Germanic class 2 weak verbs in *-ōną. The final consonant of the stem is nonpalatalized throughout, meaning that any consonant-initial endings also start with a nonpalatalized consonant.
See Category:Old Irish class A I present verbs for a list of verbs belonging to this class.
A sample verb for this class is marbaid (“to kill”). The endings are as follows:
Present indicative
|
|
1st sg.
|
2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| Absolute
|
marbu / marbaim
|
marbai
|
marbaid
|
marbmai
|
marbthae
|
marbait
|
marbthair
|
marbtair
|
| Conjunct
|
·marbu / ·marbaim
|
·marbai
|
·marba
|
·marbam
|
·marbaid
|
·marbat
|
·marbthar
|
·marbtar
|
| Relative
|
|
|
marbas
|
marbmae |
|
marbtae
|
marbthar
|
marbtar
|
Imperfect indicative
| 1st sg.
|
2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| ·marbainn
|
·marbtha
|
·marbad
|
·marbmais
|
·marbthae
|
·marbtais
|
·marbthae
|
·marbtais
|
Imperative
| 2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| marb
|
marbad
|
marbam
|
marbaid
|
marbat
|
marbthar
|
marbtar
|
The letter ⟨t⟩ stands for /d/ in all third-person plural and passive plural endings.
See Appendix:Old Irish delenition for the change of ending-initial ⟨th⟩ to ⟨t⟩ after certain consonants.
In some cases, a vowel is inserted (historically speaking, fails to be deleted) before consonant-initial endings. This vowel is found especially after stems ending in a consonant cluster that cannot be followed by a third consonant, and after stems ending in one of the dental obstruents /t d θ ð/, but it also sometimes found in other cases. When this vowel appears, the initial consonant of the ending is in most cases palatalized. In addition, a consonant cluster that cannot end a word is broken up by an epenthetic vowel in the second-person singular imperative. An example is láthraid (“to arrange”):
Present indicative
|
|
1st sg.
|
2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| Absolute
|
láthru / láthraim
|
láthrai
|
láthraid
|
láthraimmi
|
láthraithe
|
láthrait
|
láthraithir
|
láthraitir
|
| Conjunct
|
·láthru / ·láthraim
|
·láthrai
|
·láthra
|
·láthram
|
·láthraid
|
·láthrat
|
·láthrathar
|
·láthratar
|
| Relative
|
|
|
láthras
|
láthraimme |
|
láthraite
|
láthrathar
|
láthratar
|
Imperfect indicative
| 1st sg.
|
2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| ·láthrainn
|
·láthratha
|
·láthrad
|
·láthraimmis
|
·láthraithe
|
·láthraitis
|
·láthraithe
|
·láthraitis
|
Imperative
| 2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| láthar
|
láthrad
|
láthram
|
láthraid
|
láthrat
|
láthrathar
|
láthratar
|
A sample verb for this class is molaidir (“to praise”). The endings are as follows:
Present indicative
|
|
1st sg.
|
2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| Absolute*
|
molur
|
molthar
|
molthair
|
molmair
|
molthae
|
moltair
|
molthair
|
moltair
|
| Conjunct
|
·molur
|
·molthar
|
·molthar
|
·molmar
|
·molaid
|
·moltar
|
·molthar
|
·moltar
|
| Relative
|
|
|
molthar
|
molmar |
|
moltar
|
molthar
|
moltar
|
| *In practice, A I deponent verbs almost always use nondeponent endings in the absolute inflection.
|
Imperfect indicative
| 1st sg.
|
2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| ·molainn
|
·moltha
|
·molad
|
·molmais
|
·molthae
|
·moltais
|
·molthae
|
·moltais
|
Imperative
| 2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| molthae
|
molad
|
molam
|
molaid
|
moltar
|
molthar
|
moltar
|
Here again, certain consonant clusters take a vowel before consonant-initial endings, e.g. labraithir (“to speak”):
Present indicative
|
|
1st sg.
|
2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| Absolute*
|
labrur
|
labraither
|
labraithir
|
labraimmir
|
labraithe
|
labraitir
|
labraithir
|
labraitir
|
| Conjunct
|
·labrur
|
·labraither
|
·labrathar
|
·labrammar
|
·labraid
|
·labratar
|
·labrathar
|
·labratar
|
| Relative
|
|
|
labrathar
|
labrammar |
|
labratar
|
labrathar
|
labratar
|
| *In practice, A I deponent verbs almost always use nondeponent endings in the absolute inflection.
|
Imperfect indicative
| 1st sg.
|
2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| ·labrainn
|
·labratha
|
·labrad
|
·labraimmis
|
·labraithe
|
·labraitis
|
·labraithe
|
·labraitis
|
Imperative
| 2nd sg.
|
3rd sg.
|
1st pl.
|
2nd pl.
|
3rd pl.
|
Passive singular
|
Passive plural
|
| labraithe
|
labrad
|
labram
|
labraid
|
labratar
|
labrathar
|
labratar
|
- McCone, Kim (1997) The Early Irish Verb (Maynooth Monographs 1), 2nd edition, Maynooth: An Sagart, →ISBN, page 27
- Strachan, John, Bergin, Osborn (1949) Old-Irish Paradigms and Selections from the Old-Irish Glosses, Dublin: Royal Irish Academy, →ISBN, pages 34–43
- Thurneysen, Rudolf (1940, reprinted 2017) D. A. Binchy and Osborn Bergin, transl., A Grammar of Old Irish, Dublin Institute for Advanced Studies, →ISBN, pages 352–79
