Ceacht 5:
an bhfuil?	is, are?	[int. part]+[dep form of v tá] #ecl.#	
sí	she	[pron]	
tá sí	she is	[v]+[pron]	
an bhfuil sí?	is she?	[int. part]+[dep. form ‘tá’ #ecl.#] +[pron]	
níl sí	she is not	[neg. verb]+[pron]	
anseo	here	dem adv. ( adv. of place )	
ansin	there	dem adv	
istigh	inside	adv	
amuigh	outside	adv	
thuas	above	adv	
thíos	below	adv	
sa	in the	prep.pron (=i+an)	
sa ghairdín	in the garden	[prep.pron (=i+an)]+[n m4] # len. #	
agus	and	conj	
a Sheáin	(addressing)Seán	voc case # len.#	
freisin	also	adv	
ceart	right	n m1	
ceart go leor	right enough	[adj.] + [adv]	

The little word an in this lesson is called the interrogative particle and is used to turn a statement into a positive question.  When we ask a question in Irish, we place this interrogative particle in front of the verb.  So we get the word order:

[int. part] + [verb]

An causes eclipsis of a following verb.  Please refer to the table on p144 of Book Two for the effect of eclipsis.

The word bhfuil is called the dependant form of the verb tá (is) which was introduced in Lesson 1.  Not all Irish verbs have a dependant form. 

Tá sí - She is,
An bhfuil sí? - Is she?

The little word sa (in the) causes Lenition.  Again, please refer to the table on p144 of Book Two to see the effect of Lenition.  

gairdín – garden
sa ghairdín - in the garden.