Bíonn versus Tá
When you use an adjective to describe someone but are speaking in general, shouldn't you use bíonn instead of tá? For instance, "Tá sé go maith." means he is well (right now) but if I want to say someone is careful in general, then I should actually say "Bionn sé cúramach." and not "Tá sé cúramach.", correct? I guess the version with "tá" might actually be rendered in American English as "He is being careful." For instance, if your friend is cutting something with scissors and your mother is freaking out and says, "He better watch out that he doesn't cut himself.", you might respond with, "Calm down. He is being careful." Anyhow, if this is the case, then I wonder if there are a whole class of adjectives which normally would be used with bíonn instead. Thanks in advance for your help because I am really confusing myself on the correct usage here. Ugh.Ugh. I guess I am getting confused because I am not sure if in this case being careful should be a habitual action/state. Hmmmm.

Question

Bíonn versus Tá
When you use an adjective to describe someone but are speaking in general, shouldn't you use bíonn instead of tá? For instance, "Tá sé go maith." means he is well (right now) but if I want to say someone is careful in general, then I should actually say "Bionn sé cúramach." and not "Tá sé cúramach.", correct? I guess the version with "tá" might actually be rendered in American English as "He is being careful." For instance, if your friend is cutting something with scissors and your mother is freaking out and says, "He better watch out that he doesn't cut himself.", you might respond with, "Calm down. He is being careful." Anyhow, if this is the case, then I wonder if there are a whole class of adjectives which normally would be used with bíonn instead. Thanks in advance for your help because I am really confusing myself on the correct usage here. Ugh.Ugh. I guess I am getting confused because I am not sure if in this case being careful should be a habitual action/state. Hmmmm.

Answer

When you're talking about a general state of affairs, you should use "tá".
e.g. "Tá an teach mór" doesn't mean that the house is big just at this moment in time.

When you're talking about specific occasions at separate points in time (the sort of situations in which you might use words like "go minic", "de ghnáth", "gach lá", "uaireanta"), you use "bíonn".
e.g. "Tá sé cúramach" can imply that he is a careful person in general or that he is being careful at this precise moment, depending on context; "Bíonn sé cúramach", on the other hand, means that he is regularly careful at various different moments: "Bíonn sé cúramach agus é i mbun siosúir" = He is careful when (each time) he uses scissors.

So, there is no class of adjectives which use "bíonn" rather than "tá", more or less any adjective can take either tense depending on the timeframe you want to express. You'll generally need to use "tá", unless you're specifically talking about a number of different occasions.

As well as "tá" and "bíonn", the copula ("is") is also regularly used with adjectives, generally when the adjective is emphasised: "Is mór an teach sin", "Is cúramach an duine é".