Here's why:
* Semicolons are used to connect two independent clauses that are closely related in meaning.
* Commas are used within a single clause, often separating items in a list or introducing a dependent clause.
Putting them together creates ambiguity and makes it difficult for the reader to understand the intended structure of the sentence.
Example of an incorrect usage:
* "The sun was shining; , but the air was cold."
Here's how to fix it:
* "The sun was shining; however, the air was cold." (Using a conjunctive adverb)
* "The sun was shining; the air was cold." (Removing the comma)
Exception:
There is a rare exception when using a semicolon and comma together in a complex sentence that involves lists or parentheticals.
* "The guests included John Smith, who brought his wife, Mary; and their children, Tom and Jane."
In this example, the semicolon separates the list of guests from the parenthetical information about John Smith's wife.
Overall, it's best to avoid placing a comma and semicolon next to each other unless you have a very specific reason and you are confident that the sentence's meaning will be clear to your reader.