by ChrisB Sun Nov 21, 2010 5:16 pm
1. Jim washed the bedroom, and he cleaned the window
Correct, but wordy because of the redundant "he."
2. Jim washed the bedroom and he cleaned the window
Incorrect - It is unclear what the and should join or group together. From the way this sentence is written, the reader would expect to find another thing that Jim washed following the and. For example, "Jim washed the bedroom and the car" makes sense because the car and bedroom are two objects that can be washed. Instead, this sentence means to discuss two actions Jim took so we must use the ", and" construction if we want to join together two full independent clauses. The comma in 1 makes it clear that we're joining together two independent clauses that discuss what Jim did.
3. Jim washed the bedroom, and cleaned the window
Incorrect - the portion of the sentence after the ", and" should be an independent clause. You have created a comma splice here because the second portion of the sentence can't stand alone.
4. Jim washed the bedroom and cleaned the window
Correct - and joins together two things Jim did. A comma before the and is not required because we are not joining together two independent clauses.
Chris Brusznicki
MGMAT Instructor
Chicago, IL