The boy swam in the pool all day.

Meaning: This means he moved through water using his arms and legs in a container filled with water for swimming or bathing for the whole of the time between sunrise and sunset.

Choice of Words: Swam means to move through water using your arms and legs. Pool is a container filled with water for swimming or bathing. All means the whole of something. Day is the time between sunrise and sunset.

Alternative Expressions

Related Expressions