As in many other languages, Irish adds prefixes (réimíreanna) to words to create new words. If you become familiar with the prefixes below, you may double your vocabulary!

Note that some prefixes are separated from the base word by a hyphen, and some prefixes cause lenition.

prefix meaning examples
ain- negation (in-, un-, not-)
over-
ceart (right) becomes aincheart (unjust).

fios (knowledge) becomes ainfhiosracht (overcurious).

an- very maith (good) becomes an-mhaith (very good).
ard- high, arch-

(king) becomes ardrí (high king).
deagánach (deacon) becomes ard-deagánach (arch-deacon).

ath- re- déan (do, make) becomes athdéan (redo, remake).
ban- female (-ess, -ix) údar (author) becomes banúdar (authoress).
breac-
ceann- chief, main

-headed

litir (letter) becomes ceannlitir (capital letter).
comh- mutual, joint ceol (music) becomes comhcheol (harmony).
dea- good, well scéal (news, story) becomes dea-scéal (piece of good news).
dearg- red-, real, utter gráin (hatred) becomes dearg-ghráin (intense hatred).
dé- bi-, di-, two- taobh (side) becomes déthaobhach (bilateral).
di- de-, dis-, in-, un- scéal (news, story) becomes díscéil (uninformative).
do- in-, un-, not- déanta (done, complete) becomes dodhéanta (impossible, hard to do),
droch-
dú-
for- overly, more than

pro- (in various senses)

daonna (human) becomes fordaonna (superhuman).
dubh (dark, black) becomes fordhubh (gloomy).
ainm (noun) becomes forainm (pronoun).

gar-

near; rough, approximate
great- or grand- (for relations)

amharc (sight, view) becomes gar-amharc (close-up).
meastachán (estimate) becomes garmheastachán (rough estimate)
uncail (uncle) becomes garuncail (grand-uncle).

il- many, multi-

eochair (key) becomes ileochair (master key).

in- capable of creidte (believed) becomes inchreidte (believable).
iar-
íos-
lán- total cead (permission) becomes lánchead (full permission).
leath-
meán-
mí-
mion- small, micro- insint (telling) becomes mioninsint (detailed report).
neamh-
oir-
os-
príomh- of importance, main focus cathair (city) becomes príomhchathair (capital city)
réamh- pre-, preliminary feiceáil (seeing) becomes reamhfheiceáil (foresight).
ró- over- minic (often) becomes rómhinic (too often).
sár- exceeding, ultra- riail (rule) becomes sár-riail (golden rule).
sean-


so- easy briste (broken) becomes sobhriste (fragile, easily broken).