1. "Therefore" as a Conjunctive Adverb:
* Commas: Use a comma *before* "therefore" when it acts as a conjunctive adverb connecting two independent clauses.
* Example: The storm was severe; therefore, the roads were closed.
* Semicolons: You can use a semicolon *before* "therefore" when it connects two closely related independent clauses. This emphasizes the connection between the clauses.
* Example: The storm was severe; therefore, we stayed inside.
2. "Therefore" as a Transitional Phrase:
* Commas: Use a comma *after* "therefore" when it begins a phrase that introduces or transitions to a new idea.
* Example: The storm was severe. Therefore, we decided to postpone the trip.
Important Note: Whether you use a comma or semicolon before "therefore" depends on the relationship between the clauses you're connecting.
When to Choose a Semicolon:
* Use a semicolon when the clauses are closely related in meaning and the connection between them is strong.
* The semicolon helps to show that the two clauses are equal in importance.
When to Choose a Comma:
* Use a comma when the clauses are less closely related or when the connection between them is more subtle.
* The comma indicates that the two clauses are separate but related.
Remember: If "therefore" introduces a complete sentence, you'll always use a period before it.
Example: The storm was severe. Therefore, we decided to postpone the trip.