Tá mé go maith = I am {doing} well.
/taw may guh mah/

But, you use is when explaining something that probably won’t change, for example:

Is Éireannach mé = I am Irish
/iss ay-ron-ock may/

For those of ye who have studied Spanish, Portuguese, or Italian, the difference between ‘tá’ and ‘is’ is similar (but not identical to) the difference between ESTAR / STARE and SER / ESSERE (ESTAR / STARE – SER / ESSERE); in fact, ESTAR / STARE / TÁ are also etymologically related to the word ‘state’ (as in ‘condition’) in English and SER / ESSERE / IS to the English word ‘essence’.

A common mistake beginners make is to use the verb ‘bí’ (tá)’ as an exact translation of the English verb ‘to be’. Beginners learn

tá sé mór – ‘he/it’s big
tá mé anseo – ‘I’m here’
tá tú óg – ‘you’re young’

and they learn that

sé = he/it tú = you mé = I (or ‘me’)

and that

mór = big
anseo = here
óg = young

They deduce (naturally enough) that ‘tá’ is translated as a form of the verb ‘to be’ in the present. They then form clauses such as

*Tá sé múinteoir * = ‘He’s a teacher’ (INCORRECT)

*Tá mé Éireannach * = ‘I’m Irish’ (INCORRECT)

Unfortunately, these structures are incorrect; they’re as incorrect as ‘está profesor’ or ‘estoy irlandés’ are in Spanish (this mistake is commonly referred to as the ‘tá sé fear’ structure). ‘Tá’ is used with adjectives to express a state or condition; it is not used (on its own) for classification or identification sentences, i.e., it can’t be used to answer the question ‘what is he/it?’. For these structures you use ‘is’

Is múinteoir é = ‘He’s a teacher’

Is Éireannach mé = ‘I’m Irish’ (or ‘I’m an Irishman’)

HOWEVER

It is possible to use ‘tá’ in a classification sentence but ONLY with the preposition ‘i’ (‘in’).

so

*Tá sé múinteoir * = ‘He’s a teacher’ (INCORRECT)

BUT

Tá sé ina mhúinteoir = ‘He’s a teacher’ (CORRECT)

(literally ‘he’s in his teacher’)

‘Tá sé ina mhúinteoir’ normally has the implication of ‘he’s a teacher (now)’ i.e., ‘he has become a teacher’.

‘Bí (tá)’ is also used in Connacht and Ulster with ‘i’ in strutures which replace the copula ‘is’ (but without the implication of ‘become’)

X + ‘bí’ + ‘i’ (+ pronoun)

Muinteoir atá ann. = Is múinteoir é. (= ‘He’s a teacher’)

Banaltra atá inti. = Is banaltra í. (= ‘She’s a nurse’)

To recap – you can say

Is múinteoir é.

Múinteoir is ea é. (more about this structure later – it’s used in Munster Irish)

Tá sé ina mhúinteoir.

Muinteoir atá ann.

but you can NOT say

*Tá sé múinteoir.

Written by Tadhg.

Learn more about Irish Gaelic verbs online and more, at Bitesize Irish Gaelic.