The prepositions under and below are interchangeable.
Under is used much more widely. When you’re not sure which word to use, use under. It is more likely to be correct.
Both below and under can mean ‘lower than’.
All the common uses of below are related to the idea of “lower or less than,” as in these examples:
- The game is suitable for children below the age of 10.
Below is preferred when one thing is not directly under another.
- The sun disappeared below the horizon.
In measurements of temperature and height we use below.
- The temperature is five degrees below zero.
Under is preferred when something is covered by what is over it.
- He was wearing a blue shirt under his sweater.
Under can also mean “guided or controlled by,” as in:
- The cafe is under new management.
To mean ‘less than’ or ‘younger than’ we use under.
- There were under ten students in the class.