Oops. Sorry, a Sheáin, for dropping it on you before you were prepared for it, but the question was for my benefit more than yours. Sorry for the inconvenience.

If it is any consolation, the link you found was on the right track.
The answer is kind of in your signature, as well, but basically there are two "verbs" in Irish (the copula
is and the verb
bí (
tá)) that correspond to the verb "to be" in English, and it is necessary to distinguish them to make sense in Irish (though other English speakers will probably understand what you are trying to say).
The copula is used to equate two nouns:
Is fear mé "I am a man" (not
tá sé fear*)
Is foghlaimeoir é "He is a learner"
Is Seápánach í mo bhean "My wife is Japanese", i.e., "a Japanese person"
For "A is a B" in English, the pattern in Irish is usually
Is B (é/í) A.
Tá is used for states and descriptions:
Tá mé anseo. "I am here"
Tá sé tinn "He is sick".
Tá an aimsir go hálainn. "The weather is beautiful."
Use
tá if the complement of the sentence (the part that isn't the subject) is an adjective or an adverb.
That's the basics. Beginners need to starting look out for this sooner rather than later.
The situation in your hint in the game, however, is a bit more complicated because
amárach, etc., are usually adverbs but were functioning as nouns in the sentences in question. In fact, the situation is so special I am not even sure if I am right or if your original is correct, which is why I asked for confirmation or correction.
Again, sorry for dropping it on you before you were ready. One day you may look back on this and say "oh, so _that's_ what he was on about."