What punctuation should be used to separate two phrases in a compound sentence?

In a compound sentence, which consists of two independent clauses that can stand alone as separate sentences, a semicolon is the appropriate punctuation to separate the phrases. The semicolon indicates a close relationship between the clauses while still allowing each to maintain its independence.

Using a semicolon helps to clarify the connection between the ideas presented in the two clauses without the need for a conjunction. It's especially useful when the clauses are lengthy or contain internal punctuation. For instance, in the sentence "I wanted to go for a walk; it was raining outside," the semicolon effectively links two related but complete thoughts.

A comma might be used in conjunction with a coordinating conjunction like "and" or "but," but it is not sufficient on its own for separating independent clauses in compound sentences when no conjunction is present. An ellipsis is generally used to indicate omitted text, and a colon is typically employed to introduce lists or elaborate on the preceding clause rather than to connect two independent clauses.