"Columbus", "Western Wagons", and "The Other Pioneers" Spelling Strategy

Adding "ous" to words that end in y.
Rule 1: If a word ends in a consonant and then the letter "y", drop the y if the sound it represents disappears.
Rule 2: If a word ends in a consonant and then the letter "y", change the "y" to an "i" and add "ous".
*Exceptions to this rule are the words beauty and pity. For these words change the "y" to an "e" and add ous.
Rule 3: If a word ends in a vowel (a, e, i, o, u) and the letter "y", just add "ous".