What do the following four groups of words suggest?

Group I
CANDLE           
CHOP                
FIDDLE           
JOY               
MATCH           
SLAP               

Group II
BROWN
CORNER
FIELD
GRIND
MILL
SAND

Group III
BACK
COLLAR
HAM
HERRING
WHALE
WISH

Group IV
BUZZ
CATCH
PASS

Answer:

The first group lists STICKS, the second STONES, the third BONES, and the fourth suggests WORDS.

This suggests the badly mistaken rhyme: Sticks and stones may break my bones, but words will never hurt me.