Teach (one) a lesson American British verb phrase
To counsel one to refrain from engaging in undesirable behavior in the future by exposing him to the negative consequences of his actions
Having my phone left in class really taught me a lesson - I'll never careless.
I intended to teach the newcomer a lesson for failing to follow company's regulations.
Will you stop resorting violence to friend or am I going to teach you a lesson?
The verb "teach" should be conjugated according to its tense
White lie
Ken: Yesterday I lost the watch that my girlfriend presented to me. Should I tell her this thing?
Lily: Certainly Not! Your girlfriend will be angry with you. Children and fools tell the truth.