Final e of a primitive word is retained on taking a suffix beginning with a consonant: as, pale + ness = paleness; large + ly = largely.
Exception 1.—When the final e is preceded by a vowel, it is sometimes omitted; as, due + ly = duly; true + ly = truly; whole + ly = wholly.
Exception 2.—A few words ending in e drop the e before a suffix beginning with a consonant: as, judge + ment = judgment; lodge + ment = lodgment; abridge + ment = abridgment.
Rule III.—Final "y" preceded by a Consonant.
Final y of a primitive word, when preceded by a consonant, is generally changed into i on the addition of a suffix.
Exception 1.—Before ing or ish, the final y is retained to prevent the doubling of the i: as, pity + ing = pitying.
Exception 2.—Words ending in ie and dropping the e, by Rule I. change the i into y to prevent the doubling of the i: as, die + ing = dying; lie + ing = lying.
Exception 3.—Final y is sometimes changed into e: as, duty + ous = duteous; beauty + ous = beauteous.
Rule IV.—Final "y" preceded by a Vowel.
Final y of a primitive word, when preceded by a vowel, should not be changed into an i before a suffix: as, joy + less = joyless.