Which is a complete sentence?

Which of the following sentences is a complete sentence?

• During the game, the children hid behind the large tree.
• Dad gave Mom a bunch of flowers, she hugged him.
• It gets hot in the city the mountains are much cooler.

The complete sentence is: "During the game, the children hid behind the large tree."

Explanation:

During the game, the children hid behind the large tree.

The second sentence contains a comma splice which makes it a grammatically incorrect sentence. A comma splice is when two independent clauses are joined together with only a comma instead of a conjunction or appropriate punctuation.

Dad gave Mom a bunch of flowers, she hugged him.

This sentence is not a complete sentence as it lacks a proper separation between the two independent clauses. It should be separated by a period or a conjunction to be considered grammatically correct.

It gets hot in the city the mountains are much cooler.

This sentence is also not a complete sentence because it does not have end punctuation or a coordinating conjunction after the first independent clause. This lack of proper punctuation makes the sentence grammatically incorrect.