How to spell AFFECTIVENESSES correctly?

The correct spelling for "affectivenesses" is actually "effectivenesses". It refers to multiple instances of effectiveness. To avoid the confusion, it is recommended to use the singular form "effectiveness" when referring to a single instance and reserve the plural form for multiple instances.

Excatally

• exact
• exacted
• exactingly
• exactly
• exacts
• executable
• exotically
• extol
• inexactly
• oxtail