They built a sandcastle together on the beach.

Meaning: This sentence describes two or more people working together to create a structure made of sand on the beach.

Choice of Words: Sandcastle is a structure made of sand, usually built on a beach. Together means in the company of another or others. When you put them together, "Built a sandcastle together" means they worked together to create a structure made of sand on the beach.

Alternative Expressions

Related Expressions