Rule 22 refers to -til -ful as endings. Till and full, written alone, have two l's, but when acting as a suffix only one l is written.
For example: un til, beau ti ful.
Watch the tutorial videos below to see how the Spelling Tools, Spelling Rule 22 and Reading Tools are used to spell challenging words.
Special Note:
Not all words will follow the spelling rule. These are called exceptions. If 90% or more words follow this rule then this is still a great tool to help become a proficient speller. Language experience will deal with the rest.