Here's why:
* "Respectively" acts as an adverb. It modifies a list of items and clarifies their corresponding order.
* Adverbs typically don't require a comma before them.
Example:
* Incorrect: The red and blue teams scored, respectively, 3 and 2 goals.
* Correct: The red and blue teams scored 3 and 2 goals, respectively.
However, there are rare exceptions. If you have a particularly complex sentence with multiple clauses and "respectively" is in a specific position, you might use a comma for clarity.
Example:
* Correct: The red and blue teams scored 3 and 2 goals, respectively, despite the challenges they faced.
In general, it's safer to avoid a comma before "respectively" and focus on keeping your sentences concise and clear.