doinchoisc

Old Irish

Etymology

From to- +‎ in- +‎ com- +‎ seichid (“to declare”). Its original form was something like *do·inchosaig (compare in·coisig) which led to the t-preterite encountered in the poems of Blathmac due to the influence of saigid and aigid, which both had t-preterites.

The lenition instead of nasalisation of the combination of in- and com- is due to the prefix in- coming from both Proto-Celtic *en- and *eni- variants; *eni- caused lenition while *en- caused nasalisation. See tecosc for a nasalised doublet.

Verb

do·inchoisc (verbal noun tinchosc)

1. to inform, show
   • c. 815-840, “The Monastery of Tallaght”, in Edward J. Gwynn, Walter J. Purton, transl., Proceedings of the Royal Irish Academy, volume 29, Royal Irish Academy, published 1911-1912, paragraph 23, pages 115-179:

     Is maith immurgo lais do neuch do·inchoisc a llessai dóib cení·frecmairc coibsina.

     He thinks it well, however, for anyone, that one should show what is profitable to them, even though he does not ask for confessions.

2. to teach, instruct
   • c. 760 Blathmac mac Con Brettan, published in "A study of the lexicon of the poems of Blathmac Son of Cú Brettan" (2017; PhD thesis, National University of Ireland Maynooth), edited and with translations by Siobhán Barrett, stanza 87

     Tos·n-inchoisecht ind óen ré dénom nathrach n-umaide. Ba remib gabais crephel nathracha for díanteiched.

     At the same time he taught them the making of brazen serpents. Before them, terror seized the [other] serpents [and set them] upon swift fleeing.

Inflection

Complex, class B I present, reduplicated and t preterite

		1st sg.	2nd sg.	3rd sg.	1st pl.	2nd pl.	3rd pl.	Passive sg.	Passive pl.
Present indicative	Deut.			do·inchoisc
	Prot.
Imperfect indicative	Deut.			do·inchoisced
	Prot.
Preterite	Deut.
	Prot.
Perfect	Deut.			do·rinchoisc; to·inchoisecht
	Prot.
Future	Deut.
	Prot.
Conditional	Deut.
	Prot.
Present subjunctive	Deut.
	Prot.
Past subjunctive	Deut.
	Prot.
Imperative
Verbal noun		tinchosc
Past participle
Verbal of necessity

Mutation

Old Irish mutation
Radical	Lenition	Nasalization
do·inchoisc (pronounced with /h/ in h-prothesis environments)	unchanged	do·n-inchoisc
Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs.

Further reading

• Gregory Toner, Sharon Arbuthnot, Máire Ní Mhaonaigh, Marie-Luise Theuerkauf, Dagmar Wodtko, editors (2019), “do-inchoisc”, in eDIL: Electronic Dictionary of the Irish Language