Caibidil a Dó: The Adjective (an Aidiacht)

preceding adjectives and other prefixes (na réimíreanna)

• many pronominal adjectives, like uile = all, gach = every , etc. e.g.: gach teach = every house
• possessive pronouns (in Irish termed as "possessive adjectives ") e.g.: mo theach = my house
• adjectively used numbers (cardinal- and ordinal numbers) e.g.: an tríú teach = the third house, trí theach = three houses

All other (monosyllabic) adjectives may then only precede the noun in the form of a prefix (réimír). A differentiation between prefixes, as is made in German, and preceding adjectives is generally not possible.

• Some adjectives occur only in this form as the prefix auf (e.g. deá- = good , droch- = bad )
  e.g.: deá-bhád = a good boat, drochbhád = a bad boat
• By some adjectives this form is preferred (e.g.: sean- = alt).
  e.g.: seanfhear = an old man (rather wrong: fear sean)
• By most of the adjectives this is less common; if so, it is for forming set terms. They would in other cases come after the noun.
  e.g.: ardrí = High King , but: sliabh ard = high mountain
• Some prefixes may also further modify normal adjectives. In English, one would use adverbs like "very", "really", "too" etc.
  e.g.: an-mhaith = very good, fíormhaith = really good, rómhaith = too good .
  Amazingly, many of these prefixes can be used with other parts of speech.
  e.g.: an-charr = a great car (lit.: "very-car").
• The prefixes so-, do-, in- can today only modify verbal adjectives (more exact and more complicated: only the genitive of the verbal noun), see also in that section.

Some rules for using these prefixes:

• There is lenition following every one of these prefixes, except after éa- = un-, there eclipsis, but in modern spelling with the omission of the eclipsing sound (e.g.: éa + cóir - éagóir = injustice)
• prefix and noun are always written together (sean + bean = seanbhean = old woman ), except:
• an- and dea- always with a hyphen (an-bhean, dea-bhean)
• Hyphens otherwise only by multiple prefixes (e.g.: droch-sheanbhád = bad old boat) or when the same phonemes collide (e.g.: ró-óg = too young, sean-nós = old style )

Some examples: (There are many more prefixes than those mentioned here.)

prefix	translation	example	translation
droch	bad	drochbhád	a bad boat
sean	old	seanbhean	an old woman
barr	excellent	barrthuirseach	extremely tired
dea-  (deá-)	good	dea-cheol	good music
an-	very	an-charr	great car
ró (ro)	too much	róshean	too old
fior	really	fíormhaith	really good
mí	un-	míshásta	unhappy
éa	un-	éagóir	injustice
síor	eternal	síordheifir	eternal rush
corr	odd	corruimhir corrdhuine	odd number odd person
il	many, poly-	ilteangach	polyglot
leath	half	leathchéad	half hundred = 50
priomh	primary, main	priomhtheanga	primary language
ard	high, arch-	ardeaspag	archbishop
ath	re-	Athbhliain	New Year
so	easily	sobhriste	fragile
do	impossible, difficult	dodhéanta	impossible to do
in	possible	inite	edible

Some of these prefixes end (in Munster) in -a, if they precede a consonant (e.g. ana-mhaith = very good)

[ 1 ] amlaidh etymologically actually a prepositional pronoun made of amhail + eadh (old form of ea) = "like it "