All students should know rules for suffix spelling changes.

The English language rules with highest validity and utility are those relating to suffix spelling changes.

Students at all grade levels can be taught the rules, drilled in their application, and expected to apply them. Start by teaching each rule and having students do the drill cards. Once all the rules have been covered and posted, add suffixes to words on spelling tests. Insist on application of the rules in written work. If students get careless when adding suffixes or forget the rules, they can repeat cards.