A comma is used before especially when especially is used to set off a parenthetical clause, usually at the end of a sentence. See this ELU answer. No comma is used when especially is not being used to set off a parenthetical clause.
How do you use especially in a sentence?
Use especially when something stands out from all the others, and you want the meaning of “particularly,” as in these examples:
- She can't be sure she will win, especially at this early stage of the campaign.
- The appetizers and especially the soup were delicious.
Should you start a sentence with especially?
You may use words like 'especially' or 'because' at the beginning of the sentence as long as you provide a supporting clause after it. Because my dog had fleas, I had to make him sleep outside. Especially when the weather report predicts rain, you should have an umbrella in your car.
