When to use a comma after "but":
* When "but" connects two independent clauses. An independent clause can stand alone as a sentence.
* Example: "The dog barked loudly, but the cat slept soundly."
* When "but" introduces a contrasting element. This is similar to the first point, but the emphasis is on the contrast.
* Example: "I was tired, but I wanted to stay up and watch the movie."
When not to use a comma after "but":
* When "but" connects a dependent clause to an independent clause. A dependent clause cannot stand alone as a sentence.
* Example: "I went to the park, but I forgot my frisbee."
* When "but" introduces a phrase or a single word.
* Example: "I was hungry, but only a little."
Key takeaway: The rule of thumb is to use a comma after "but" if it connects two complete sentences (independent clauses) or if it introduces a contrasting element. Otherwise, no comma is needed.
It's also important to remember that commas are not always governed by hard-and-fast rules. Sometimes, the best way to decide whether or not to use a comma is to read the sentence aloud and see if it sounds right. If it does, then the comma is probably correct.