Final answer:
The sentence can be punctuated correctly as follows: We are having peas and carrots, roast beef, and cake for dinner. Commas should be placed to separate the items in the list. In this case, the items in the list are peas and carrots, roast beef, and cake.
Step-by-step explanation:
The student's question requires proper comma placement within sentences, which can help convey the intended meaning more clearly and ensure the writing is grammatically correct. Here are the revised sentences:
- I finally found my keys, and I got to work just in time.
- Mrs. Contreras threw out her old coffee table and cleaned the carpet.
- Taking the elevator to the roof, we hoped we could see the skyline and the bay.
- Though Susan wasn't feeling well, she went to the store anyway and bought ice cream, pizza, and candy.
- I let my neighbor borrow my phone because she said hers was tapped by the police.
It's important to recap that you should use a comma before a coordinating conjunction joining two main clauses, after introductory elements, and to set off non-essential information. It is not necessary to place commas around information that is essential to the sentence's meaning.
Additionally, style guides vary on the use of the serial comma, often known as the Oxford comma, which is the comma before the coordination conjunction in a list of three or more items, but generally, it's recommended for clarity. Consistency in using the serial comma is key.