Comma After Introductory Clauses Introductory clauses are
dependent clauses which are found at the beginning of the
sentence (although they can be moved to the end of the sentence,
too, without confusing the meaning of the sentence). After a
dependent introductory clause, we use a comma to separate the
introductory clause from the independent clause. The dependent
introductory clause may start with an adverb or conjunction like
although, if, or when. As the man was walking into the store, he
came face-to-face with his childhood sweetheart. Because the
rain was torrential, the day’s Little League games were
postponed. Grabbing her umbrella, Kate raced out of the house.
Now then, we should head back home because the baby needs a nap.