Which statement reflects a rule for affix usage mentioned in the material?

• A. Affixes can always be added to any root word
• B. An affix cannot be used if it is blocked by an existing form
• C. Affixes must be used only with nouns
• D. Affixes are never used with English roots

Answer: (B)

The rule being tested is that affix usage is governed by blocking: you cannot attach an affix if an existing form on the root blocks it. This means the language prevents adding an affix when the root already has a form that would make that affix redundant, illegal, or conflict with the current morphology. In practice, this keeps word formation consistent and avoids creating forms that double up on meaning or violate the established structure.

That’s why the statement about an affix not being usable when blocked by an existing form is the best reflection of how affixes operate. The other ideas don’t fit the real behavior: affixes aren’t limited to nouns, they’re used with many parts of speech; English roots do take affixes; and affixes don’t simply “always” attach to any root—blockage and compatibility matter.