to give something valuable to someone who does not understand that value: to cast pearls before swine

to be useful, to help

present; gift

A gold coin of feudal Japan, with a face value of one 両 (ryō).

cat

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

a cat

cat