Ceacht 15:
an bhfuil sé?	is he?	[interr. vb. part]+[pres. dep. form v. #ecl.# "bí"]+[pron]	
nach bhfuil sé?	isn't he?	[neg. interr. vb. part]+[pres. dep. form v. #ecl.# "bí"]+[pron]	
cá bhfuil sé?	where is he?	[inter adv]+[pres. dep. form v. #ecl.# "bí"]+[pron]	
an scian	the knife	[def. art.]+[n f2 ]	
an forc	the fork	[def. art.]+[n m1 ]	
an spúnóg	the spoon	[def. art.]+[n f2]	
an pláta	the plate	[def. art.]+[n m4]	
an cupán	the cup	[def. art.]+[n m1]	
an fochupán	the saucer	[def. art.]+[n m1]	
sin	that	pronoun / determiner	
sa chupán	in the cup	[prep.phrase[i+an]] + [n m1 #len.#]	
gabh mo leithscéal	excuse me	[v.] + [ poss. Pron.] + [ n m1]	
maith an cailín	good girl	[adj.]+[part.]+[n m4]	
maith an buachaill	good boy	[adj.]+[part.]+[n m3]	

Using the copula "is" to emphasis an adjective:  One of the functions of the copula is to emphasise a particular word in a sentence.  When we wish to emphasise an adjective in the present tense - such as "maith" for example - we do it by writing "Is maith" and placing "an" in front of the noun, even though we're not using that "an" to mean "the".  So, written in full, "Is maith an cailín!" means "Good girl!" although the copula itself can often be omitted, leaving us with "Maith an cailín".  You will frequently see and hear this expression as a form of praise for somebody who has done well in something.