Ceacht 13:
nach	is … not?	neg. interr. vrb. part.	
nach bhfuil?	isn't? aren't?	["]+pres. dep. form v. #ecl.#  "bí" (question form)	
nach bhfuil sé?	isn't he , it?	["] + [pron.]	
nach bhfuil siad?	aren't they?	["] + [pron.]	
ar an tsráid	on the street	[prep.]+[def. art.]+[n f2  # prefix #]	
ar an mbóthar	on the road	[prep.]+[def. art.]+[n m1  #ecl.#]	
ar an mbus	on the bus	[prep.]+[def. art.]+[n m4  #ecl.#]	
ar an leoraí 	on the lorry/truck	[prep.]+[def. art.]+[n m4]	
ar an traein	on the train	[prep.]+[def. art.]+[n f5]	
ar an eitleán	on the aeroplane	[prep.]+[def. art.]+[n m1]	
é	it	pron	
feicim é	I see it	[v (+subj.)]+[pron]	
go raibh maith agat	thank you	vb phrase	
ní	-	[neg. vb. part.]	
ní fheicim é	I don't see it	["]+[v (+subj.) # len.# ]+[pron]	
an páipéar	the paper	[def. art.]+[n m1]	

feicim (I see): This is the combined form (verb + subject) of the irregular verb feic (see). 

nach (is...not?):  This is the negative interrogative verbal particle which takes the dependant form of the verb and causes eclipsis.

ar an (on the):  This is another example of a preposition (ar) used with the singular definite article (an) to cause eclipsis.

é (he / it):  When "he" or "it" is the object of the sentence one uses "é" instead of "sé".

ní:  This negative verbal particle negates a regular verb and causes lenition.