Many of the prepositions have combination forms with the common pronouns. There are prepositional pronouns, special combined forms of prepositions and pronouns that should be used.

	singular			plural
	1st (me)	2nd (you)	3rd (he, it / she)	1st (us)	2nd (you-all)	3rd (them)
ag (at)	agam	agat	aige aici	againn	agaibh	acu
ar (on)	orm	ort	air uirthi	orainn	oraibh	orthu
as (from)	asam	asat	as aisti	asainn	asaibh	astu
chuig (to)	chugam	chugat	chuige chuici	chugainn	chugaibh	chucu
de (off)	diom	diot	de di	dinn	dibh	diobh
do (to/for)	dohm	duit	dó di	dúinn	daoibh	dóibh
faoi (under)	fúm	fút	faoi fúithi	fúinn	fúibh	fútha
i (in)	ionam	ionat	ann inti	ionainn	ionaibh	iontu
le (with)	liom	leat	leis léi	linn	libh	leo
ó (from)	uaim	uait	uaidh uathi	uiann	uaibh	uathu
trí (through)	tríom	tríot	tríd tríthi	trínn	tríbh	tríothu
um (around)	uman	umat	uime uimpi	umainn	umaibh	umpu
roimh (before)	romhan	romhat	roimhe roimpi	romhainn	romhaibh	rompu
thar (over)	tharam	tharat	thairis	thairainn	thariabh	tharstu
idir (between)	idir mé	idir tú	idir é idir í	eadrainn	eadraibh	eatarthu

Prepositions can cause some changes to words that follow them.

	words beginning with a consonant	words beginning with a vowel
ag (at)	no change	no change
ar (on)	lenition (not l, n, r)	no change
as (from)	no change	no change
chuig (to)	no change	no change
do (to, for)	lenition (not l, n, r)	becomes d'
go (to)	no change	adds h-
go dti (to)	no change	no change
i/in (in)	urú (not l, m, n, r, s)	no change
le (with)	no change	adds h-
ó (from)	lenition (not l, n, r)	no change

When these prepositions are used with the singular article 'an', some of them can change to combined forms, such as:

do + an	dan (to the, for the)
i + an	sa (in the), used before consonants
in + an	san (in the), used before vowels
le + an	leis an (with the)
ó + an	ón (from the)

Finally, when used with the plural article 'na', there are a few combined forms

: