Rule 25 refers to the phonogram 'ck'. The phonogram 'ck' may be used at the end of a word or the end of a syllable, after a vowel saying its first sound.
For example: clock, chick en, lick, luck.
For everything else use the phonogram 'k'.
For example: book, bark, cask.
Watch the tutorial videos below to see how the Spelling Tools, Spelling Rule 25 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.