"I am not able to get that."
Translation:Nílim in ann é sin a fháil.
Note that 'in ann' is the same as 'ábalta' which sounds more like the word able if you ask me. Both are correct. The latter being easier to say but less fancy if you will.
Generally, a personal pronoun is optional for using sin as a demonstrative pronoun. It would probably be needed only in places where a personal pronoun would be needed, such as in a copular statement with a personal pronoun as a subject, e.g. Is claíomh é sin! (“That’s a sword!”).
Okay, thanks, that makes sense. Then I guess I was just confused about inconsistent use I saw, which is fine if it's completely optional. I'll report it the next time when my version isn't accepted.
In the copular statement I would indeed have used the pronoun because I'd consider "sin" definite (so the pronoun would be a subpredicate/subsubject). Not sure if that's the right explanation, but it seems to give the right results anyway.
In a copular identification statement like Is é an claíomh é sin! (“That’s the sword!”), the first é is the subpredicate. I’m not sure if the é in these example copular sentences’ é sin would be considered the subsubject of the subject sin, or if é sin would together be considered a subject without a subsubject.