Ceacht 28:
ní	negatives a verb	neg. v. part.	
níor	negatives a verb	neg. v. part	
é	it	pron.	
é sin	that	demon. pron.	
ní dúirt mé	I didn't say	[neg. v. part.]+[v.] + [pron.]	
ní dhearna mé	I didn't do	[neg. v. #len.#  part.]+[v.] + [pron.]	
ní bhfuair mé	I didn't get	[neg. v. #ecl.#  part.]+[v.] + [pron.]	
ní fhaca mé	I didn't see 	[neg. v. #len.#  part.]+[v.] + [pron.]	
níor thug mé	I didn't give	[neg. v. #len.#  part.]+[v.] + [pron.]	
níor chuala mé	I didn't hear	[neg. v. #len.#  part.]+[v.] + [pron.]	
mo 	my	pron.	
do	your (sg.)	pron.	
mo phíopa	my pipe	[pron] + [ n. m4. #len.#]	
mise	I 	pron.	
sa halla	in the hall	[prep.pron.( =i+an )] + [ n. m4]	
do phóca	your pocket	[pron.] + [ n. m4. #len.#]	
ansin	there	adv.	

Another irregular verb - clois (hear) is introduced here. In lesson 27 we saw the regular verb "D'éist.....le..." being used to express "heard". 
This week's lesson gives us an alternative verb, clois, which is one of the 11 irregular verbs, shown here in the past tense: 	Clois (hear) = chuala (heard)
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mo (my) and do (your): These two personal pronouns cause lenition of the following word.

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ní / níor:
ní is used to make 6 of the irregular verbs negative in the past tense:

ní dúirt (did not say) 		- see this lesson
ní dhearna (did not do) 	- see this lesson
ní bhfuair (did not get) 	- see this lesson
ní fhaca (did not see) 		- see this lesson

It is also used with the past tense irregular verb bí (is) as we saw in lesson 17; ní raibh (was not).

níor is used to make all regular verbs negative in the past tense. It is also used in the past tense of some irregular verbs:

níor thug (past tense of tabhair" - give) 	- see lesson 27,
níor chuala (past tense of clois - hear) 	- see this lesson.

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"I gave only three shillings...":  To express the word "only" in a sentence such as this we must make the verb negative and include the word ach (but) after the subject.  As we see above, a verb is made negative in the past tense by putting ní or níor in front of it so the English translation of 
"Níor thug mé ach trí euro" would be "I did not give but three euro."