It would seem rather a strange question, given the amount of text I've been reading, but I haven't yet really got an answer to the question how to say "THEY ARE BIG".

Shouls there be an agreement between the predicate big and the subject?

Or it's free?

'is mór iad' when you are introducing that they are big for the first time /saying they are etc

thanks.

So it's not in agreement.

Predicate adjectives do no need agreement, and so are unchanged (they are big)

Attributive adjectives are changed tho , depending on context (those big people)

The reason for this might come down to historically the attributive adjective standing next to the noun and so changing with it.

Adjectives used predicatively are mostly used with the verbs tá, bí and the copula so they sit between the adjective and noun so there must not have developed agreement

Here is another way of thinking about it: linking verbs in English, and maybe the copula too:

He is a writer
He is good

In English, 'good' is predicative as it has been shielded from the person by 'is'.

He is a good man

'Good' is attributive here, as the quality is a feature of the noun


However, in reality, functionally they are the same (at least for this simple example), only there is a structural difference from the point of view of the grammar. Here the difference is in how you state it: existentially using a verb =predicatively and nominally using a noun =attributively.

For a noun a quality is an attribute; talking in terms of predication, the statement can be true, in a sense or not -it is a statement.

For predication, maybe you could think of it as a question of something being true of something, and you can check it out; for attribution, it just is

Irish is complicated when it comes to "is". I mean for the two sentences you give, I'd translate them as follows:

Scríbhneoir atá ann.
Maith an fear é.

Indeed, that is why I beckoned the poster to think of it first on a conceptual/functional level, and then delve into it structurally in English, before going on to the Irish