in- do- and so- are very useful prefixes

indéanta possible
do-dhéanta impossible
so-dhéanta easily done

This word ionchurtha retains the older spelling rule
caol le caol agus leathan le leathan
where the vowels a, o, u, and ae before a consonant
must be followed by a, o, or u after it,
and i before a consonant must be followed by i or e after it.
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