The golden rule
caol le caol agus leathan le leathan
means slender with slender and broad with broad
The terms slender
refer to two categories of vowel
The rule caol le caol agus leathan le leathan
means that the vowel
s on either side of a
(or group of consonants) should agree;
they should both be broad
or both be slender
The rule is primarily used when you add an ending to a word (e.g., when conjugating
To satisfy the rule you may need to add a vowel
between the word and its ending.
Note that there are a few common words that do not satisfy this rule.
However, even without knowing a single word of Irish, you can apply the rule to catch many spelling mistakes!
Let's try a few examples:
- Focus on the consonant in the center, l, and look at the vowels immediately before and after.
The vowel before, o, is broad, and so is the vowel after, ú.
This word follows the rule, so there aren't any obvious spelling mistakes here. (In fact, it is spelled correctly.)
- Focus on the consonant group in the center, cf, and look at the vowels immediately before and after.
The vowel before, a is broad, but the vowel after, i is slender.
This looks like a mistake! (In fact, the correct spelling is glacfaidh).
- The flanking vowels, o and a are both broad, so this word follows the rule.
- The flanking vowels, i and e are both slender, so this word follows the rule.
- Uh oh! The vowel before, i, is slender, but the vowel after, a is broad. (In fact, the correct spelling is dóimid).
Now you are ready to find spelling mistakes in that letter from your Gaeilgeoir