Having been a gymnast, James knew the importance of exercise.

• The participial phrase acts as an adjective modifying > James.

• Having been a gymnast is the participle phrase.

Punctuation

• If the participial phrase is placed in the middle of the sentence, it should be separated with commas only if the information is not essential (unnecessary) to the rest of the sentence.

• Sid, watching an old movie, drifted in and out of sleep.

• The church, destroyed by an old fire, was never rebuilt.

Punctuation

• When a participial phrase begins a sentence, a comma should be placed after the phrase.

• Example: Arriving at the store, I found that it was closed.

• Example: Washing and polishing the car, Frank developed sore muscles.

If the participial phrase is essential to the meaning of the sentence, no commas should be used.

• The student receiving the highest grade point average will receive a special reward.

• The guy wearing the chicken costume is my cousin.