Is There a Comma Before “Since”?

Understanding when to use a comma before “since” is crucial for clear and effective writing. The word “since” can introduce time, serve as a conjunction to connect clauses, or indicate causation, and the need for a comma largely depends on its function in the sentence.

This guide will navigate through the rules, providing examples for when to include or omit a comma before “since.”

When to Use a Comma Before “Since”

Rule 1: When “Since” Introduces a Dependent Clause

Correct Usage:

• We have adopted new strategies, since the market has evolved.
• The team has been more cohesive, since the new coach arrived.

Incorrect Usage:

• We have adopted new strategies since the market has evolved.
• The team has been more cohesive since the new coach arrived.

Explanation: A comma is used before “since” when it introduces a clause that provides additional information but is not essential to the main clause’s meaning.

Rule 2: “Since” at the Beginning of a Sentence

Correct Usage:

• Since the merger, our revenue has doubled.
• Since you asked, I’ll tell you the truth.

Incorrect Usage:

• ,Since the merger, our revenue has doubled.
• ,Since you asked, I’ll tell you the truth.

Explanation: When “since” starts a sentence, it is followed by a comma after the clause it introduces, not before “since.”

Rule 3: “Since” for Causation

Correct Usage:

• She has been wary, since the incident last year.
• I’ve been thinking about changing jobs, since the industry is declining.

Incorrect Usage:

• She has been wary since the incident last year.
• I’ve been thinking about changing jobs since the industry is declining.

Explanation: Use a comma to separate “since” clauses that provide a reason or causation, adding a pause for emphasis or clarity.

Rule 4: “Since” Without a Comma for Essential Clauses

Correct Usage:

• The city has expanded since 1990.
• She has felt better since she started the new treatment.

Incorrect Usage:

• The city has expanded, since 1990.
• She has felt better, since she started the new treatment.

Explanation: Do not use a comma when “since” introduces a time frame or a cause-and-effect clause that is essential to the sentence’s meaning.

Rule 5: Using “Since” in the Middle of a Sentence

Correct Usage:

• The performance, since it was so well-received, will be extended.
• Our policy, since you haven’t read it, covers these situations.

Incorrect Usage:

• The performance since it was so well-received will be extended.
• Our policy since you haven’t read it covers these situations.

Explanation: A comma before “since” in the middle of a sentence sets off a non-essential clause for additional context or clarification.

Read More: Do You Use a Comma Before Ampersand (&)?

Rule 6: “Since” in a List

Correct Usage:

• We’ve encountered several obstacles, since the project’s inception, including budget cuts and staff shortages.
• There have been many advancements, since the early 2000s, in technology.

Incorrect Usage:

• We’ve encountered several obstacles since the project’s inception, including budget cuts and staff shortages.
• There have been many advancements since the early 2000s, in technology.

Explanation: In lists or series that include time clauses introduced by “since,” a comma may precede “since” for clarity or emphasis.

Rule 7: “Since” and Direct Address

Correct Usage:

• Since, as you mentioned, we need to improve, let’s start now.
• Since, according to your analysis, the data is flawed, we should revisit our conclusions.

Incorrect Usage:

• Since as you mentioned we need to improve, let’s start now.
• Since according to your analysis the data is flawed, we should revisit our conclusions.

Explanation: When “since” is used with a direct address or an inserted clause, commas should enclose the interrupting phrase for readability.

Rule 8: “Since” for Emphasis

Correct Usage:

• It has been, since you asked, a challenging year.
• The decision was made, since you were curious, last week.

Incorrect Usage:

• It has been since you asked, a challenging year.
• The decision was made since you were curious, last week.

Explanation: Commas around “since” can be used to emphasize the information following it, particularly in response to a question or curiosity.

Rule 9: Avoiding Commas for Essential Time Clauses

Correct Usage:

• Since 2010, the company has tripled in size.
• Since the law changed, compliance has been mandatory.

Incorrect Usage:

• Since 2010 the company has tripled in size.
• Since the law changed compliance has been mandatory.

Explanation: When “since” introduces a time clause that is essential to the sentence’s meaning, a comma is used after the clause, not before “since.”

Rule 10: “Since” in Compound Sentences

Correct Usage:

• The team has been successful, since the new strategy was implemented, and morale has improved.
• She accepted the offer, since it met all her conditions, and she starts next month.

Incorrect Usage:

• The team has been successful since the new strategy was implemented and morale has improved.
• She accepted the offer since it met all her conditions and she starts next month.

Explanation: In compound sentences where “since” introduces a reason or time within one of the independent clauses, a comma may precede and follow the “since” clause for separation and clarity.