31. When Do I Use Commas?
B. To join introductory clauses, phrases, or subordinate clauses that come before the main clause
| I. | An introductory clause or phrase acts as a qualifying or clarifying statement about the main sentence. Think of it as an addition to the main thought of a sentence. The introductory language is usually a dependent statement (see section A above). In order to indicate to the reader where the main thought begins and ends, and thus clarify the writer's point, a comma should be used after the introductory language. Again, these words are often contained in a dependent phrase anyway. |
Example: �By 1700 BC, wheat could not be grown in Mesopotamia due to salinization of the soil." |
Example: "However, the Fertile Crescent may not actually have been as fertile as the name suggests."
Example: �The Fertile Crescent may not have actually been as fertile as the name suggests, however.�
Example: �Wheat could not be grown in Mesopotamia by 1700 BC due to salinization of the soil.�
Example: �The ancient Mesopotamians developed a canal system, and the soil in the area became severely salinized.�
Example: �Mesopotamian soil became severely salinized, and the ancient Mesopotamians developed a canal system.�
Example: “Because of its unique geography, boundaries and inhabitants tended to be transient in southern Mesopotamia.”
Example: “The boundaries and inhabitants of southern Mesopotamia tended to be transient because of the area's unique geography.”