To help pupils use words well, teachers need to help them understand the meanings and acting abilities of words. Put word-formation and parts of speech into the relationship with the meanings, the author of the article has summansed some problems of words that make many teacners of primary schools consider. In author's opinion, to help pupils use words effectively, teachers need to attach to words' meanings while teaching word-formation and parts of speech. However, teachers shoudn't make pupils exhausted.