AN FORAINM COIBHNEASTA / THE RELATIVE PRONOUN
An Briseadh Cáis / The Case Crack
A.  THE GENERAL WAY THIS WORKS
If the subject on the left side of the relative pronoun 'a' is doing the action on the right side of the relative
pronoun, we say it has a 'direct object' and we treat the verb accordingly.
Relative Pronoun With A Direct Object
1 Seo é an buachaill a itheann an t-iasc. This is the boy who eats the fish.
Seo é an buachaill a phógann an cailín. This is the boy who kisses the girl.
Seo é an buachaill a phóg an cailín. This is the boy who kissed the girl.
Seo é an buachaill a bhí ag pógádh an chailín. This is the boy who was kissing the girl.
If, instead, the subject on the left side of the relative pronoun 'a' is NOT doing the action on the right side of the
relative pronoun (in other words, if the subject of the verb is on the right side of the verb and therefore on the right
side of the relative pronoun), we say it has an 'indirect object' and treat the verb accordingly.
Relative Pronoun With A Simple Indirect Object
2 Seo é an buachaill a n-itheann an t-iasc (é). This is the boy who the fish eats (him).
Seo é an buachaill a bpógann an cailín (é). This is the boy who the girl kisses (him).
Seo é an buachaill ar phóg an cailín (é). This is the boy who the girl kissed (him).
Seo é an buachaill a raibh an chailín á phógadh. This is the boy who the girl was at his kissing.
Relative Pronoun With A Dative (prepositional) Indirect Object
3 Seo é an buachaill a n-itheann an t-iasc in éineacht leis. This is the boy who the fish eats together with him.
Seo é an buachaill a bpógann an cailíin in éineacht leis. This is the boy who the girl kisses together with him.
Seo é an buachaill ar phóg an cailíin in éineacht leis. This is the boy who the girl kissed together with him.
Seo é an buachaill a raibh an chailín ag pógadh leis. This is the boy who the girl was kissing together with him.
Relative Pronoun With A Possessive ("Genitive") Indirect Object
4 Seo é an buachaill a n-itheann a mháthair an t-iasc. This is the boy who his mother eats the fish.
Seo é an buachaill a bpógann a mháthair an cailín. This is the boy who his mother kisses the girl.
Seo é an buachaill ar phóg a mháthair an cailín. This is the boy who his mother kissed the girl.
Seo é an buachaill a raibh a mháthair ag pógadh an chailín. This is the boy who his mother was kissing the girl.
B.  THE EXCEPTION
We can see that we change the treatment of the verb and the relative pronoun 'a' to clearly indicate who is doing
what.  The exception to this is if the verb has an embedded or subject pronoun which makes it so clear who/what
is doing the action that you don't need to treat the verb differently in order to know or communicate what's going
on.  In this case, it's okay to treat the verb as if you're working with a direct object.
  Relative Pronoun With Indirect Objects Treated as if Direct
Seo é an teach a bhí mé a thógáil. This is the house which I was building.
Seo é an rothar a chonaic mé tú ag marcaíocht. This is the bike I saw you riding.
Seo é an carr atáimid ag tiomáint. This is the car we are driving.
Seo é an buachaill a phógfaimís. This is the boy who we should kiss.
Seo é an buachaill a phógadar. This is the boy who they kissed.
Seo é an buachaill a phógann sí. This is the boy who she kisses.
In the last example, we see 'sí' instead of 'í', so we know exactly who is doing the kissing.  But some pronouns
(like mé, tú in some dialects, and sibh) don't have a separate form as an object, in which case we have to be
careful to use the correct direct and indirect forms of the relative pronoun and the verb to be sure people can
understand what is going on.