[danaliv]

I was wondering about this. Thanks for chiming in. I don't know Irish but I do know a bit of Scottish Gaelic, and it is as you say: there is no word for yes (or no), not even in the way the author suggests. Affirmation or negation is done by repeating the verb of the question. In the case of simple "to be" questions, that verb is either tha or 's. But a question like "have you read the book?", which would be structured "read you the book?", would be answered either "read" for the affirmative or "(not) read" for the negative.

In any event, tha—which I presume is the Scottish equivalent to Irish tá—doesn't mean yes either.