Consonant suffixes

Suffixes beginning with consonants do not often cause spelling problems: usually you tack them on to the end of a word without altering it: sincere + ly = sincerely
Exception: words ending in le change the le to ly: able/ably, subtle/subtly
Other exceptions: fully, truly, duly, wholly, argument
Common consonant suffixes are: ful, ness, ment, some, tion, sion, ly