“at night” and “in the night”
“In the night” usually refers to one particular point during the night—a short time, not throughout the night. For instance:
- I tried to call him several times in the night.
- I was awake in the night, preparing for the test
“At night” refers to any night in general. We use it when we talk about something that happens all of the night.
- ‘It’s not safe to move around at night,’ the officer said.
- He guards our house at night.