Rules for Using Commas | Grammarly
www.grammarly.com › blog › commaAug 12, 2022 · When an adverbial phrase begins a sentence, it’s often followed by a comma but it doesn’t have to be, especially if it’s short. As a rule of thumb, if the phrase is longer than about four words, use the comma. You can also use a comma with a shorter phrase when you want to emphasize it or add a pause for literary effect.