The Relative Pronoun.
In Old Irish there was a relative particle used after prepositions, and also a compound relative, but no simple relative in the nominative and accusative cases. The modern relative, in these cases, has arisen from a mistaken idea about certain particles. Before the imperfect, the past, and conditional the particle do should, strictly speaking, be used. Certain irregular but often used verbs had also an unaccented first syllable, as atá, do-ḃeirim, do-ċím, &c. These particles and syllables being unaccented were generally dropped at the beginning, but retained in the body, of a sentence, where the relative naturally occurs. Hence they were erroneously regarded as relative pronouns, from analogy with other languages.
In Modern Irish the relative particle may or may not be used in the nominative and accusative cases.
Although this is the origin of the modern relative nevertheless it is used as a real relative in modern Irish. Whether we call this a a relative particle or a relative pronoun is a mere matter of choice. We prefer the first name.
There is a relative frequently met with in authors, viz.—noċ, meaning who, which or that. This relative is not used in modern spoken Irish, in fact it seems never to have been used in the spoken language.
233. In modern Irish there are three simple relatives, the relative particles A and GO, which signify who, which, or that; and the negative particle NAĊ, signifying who … not, which … not, that … not.
The relative go is not found in literature, but it is so generally used in the spoken dialect of Munster that it must be regarded as a true relative. Go is not used as the subject or object of a verb, its use is confined to the prepositional (dative) case.
There are also the compound relatives pé, gibé, cibé, whoever, whosoever, whatever, and a (causing eclipsis) what, that which, all that.
234. The relative particle A expressed or understood, causes aspiration; but when preceded by a preposition or when it means "all that," it causes eclipsis, as do GO and NAĊ.
