Answer:
An Oxford comma is the comma before "and" "or" or "but"
Explanation:
The convertible car drove by with the top down.
The sentence which contains a spelling error is "At first, I didn’t really like it. I had never played before, so I didn’t know all of the rules, and I would get frustrated when my team lossed or I missed a goal." The word is actually spelled <em>lost</em>.
Using the vowel with no other markings.