Question

You shouldnt us commas in a sentence where items in a series are joined by

Answer 1

If you have a sentence with 3 different groups of items you would do this: I went to the store and bought apples, bananas, and oranges; a skirt, a shirt, and a headband; a pencil, a pen, and markers.

You would separate each grouping of similar items with a semi colon. But for the listing, you use commas.

Answer 2

You should use commas since many things are being listed at the same time. For example; Niaronica bought apples, bananas, pineapples and carrots from the store. Since there are many foods being listed you're supposed to use commas. Hope it helped!