Dias doibh, I have question agian and it is about questions. When I ask someone something like "Aren't you working today, Adam?" It would be "Nach bhfuil tu obair inniu, Caitlyn?" corect?
If I want to ask "Weren't you working today, Caitlyn" would it be "Nach bhi tú obhair inniu, Caitlyn?"

I found now something.. is "Nár bhi tú obhair inniu, Caitlyn?" by any chance correct?

And the negative answer in past tense for "No, I wasn't, I was ill and very tired" would be "Nior bhi me, bhi me tinn agus an-thuirseach." ?

Tá tú ag obair. = You are working.
An bhfuil tú ag obair? = Are you working? Níl. = No, I’m not. Tá. = Yes, I am.
Nach bhfuil tú ag obair? = Aren’t you working?

Bhí tú ag obair. = You were working.
An raibh tú ag obair? = Were you working? Ní raibh. = No, I wasn't. Bhí. = Yes, I was.
Nach raibh tú ag obair? = Weren’t you working.

The verb "bí" is highly irregular.

Just to add to what Labhras said, you've asked about "Adam," and now you have the pseudo-Irish name "Caitlyn." Which do you want? "Caitlyn" is an Anglicized corruption of the Irish name "Caitlín" (pronounced KATCH-leen or kat-LEEN, depending on dialect).

Redwol