The phrasal verb "let off" tends to be used more frequently in informal contexts rather than formal speech. It appears in conversational English and colloquial writing and is used to describe allowing someone to escape a penalty or not punishing them as severely as expected. For example, a teacher might "let off" a student with a warning for a minor infraction instead of assigning detention. Similarly, in law enforcement, a police officer might "let off" a driver with a warning instead of issuing a ticket for a minor traffic offense. The phrase can also be used in reference to permitting something to happen, like "letting off fireworks," where it implies the act of allowing an explosion or release. The flexibility in these contexts highlights its utility in casual discourse but limited formality.
B2
UpperIntermediate
1. To permit someone to leave or allow them to avoid punishment or duties.
The teacher let the students off early because it was a nice day.
I forgot to do my homework, but the teacher let me off with a warning.
He was caught speeding, but the cop let him off with just a ticket.
2. To cause something to explode or emit, often used in context of fireworks, alarms, or weapons.
They let off fireworks to celebrate the New Year.
She accidentally let off the alarm when she opened the door.
The soldier let off a round of shots during training.