A semicolon is a punctuation mark used to join two clauses together.. These clauses must be independent. These independent clauses are joined by a semicolon to form a complete sentence. On the other hand, a comma is used to separate clauses or objects in a sentence or phrase. A semicolon should not be used in place of a colon or comma. All three have their own duties. A colon is used when an emphasis is about to be made or when listing items. A hyphen is used to join two or more words but without spacing
From the question, the most appropriate punctuation to use is the semicolon as shown below
Gerald owed Cindy two dollars; he gave her ten because he felt bad.
It helps to join the two independent clauses together without the need to apply additional conjunction such as and. Also, there was no need to apply a capital letter after the semicolon as shown above.
