"I am not able to get that."
Translation:Nílim in ann é sin a fháil.
leabhar a léamh - "to read a book"
litir a scríobh - "to write a letter"
Uisce a ól - "to drink water"
ag léamh leabhair - "reading a book"
ag scríobh litreach - "writing a letter"
ag ól uisce - "drinking water"
Tá an leabhar á léamh agam - "The book is being read by me"
Tá an litir á scríobh aige - "the letter is being written by him"
Tá an t-uisce á hól againn - "the water is being drunk by us"
níl sé á fháil sin - "He's not getting that"
ní féidir leis é sin a fháil/níl sé in ann é sin a fháil - "He isn't able to get that"
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.