When should I use a period in a sentence?
Use a period at the end of a complete sentence that is a statement.
Examples: Mary had a little lamb.
John had a green frog.
I eat vegetables every day.
Milk makes me feel like throwing up.
If the last item in the sentence is an abbreviation that ends in a period, do not follow it with another period.
Examples: The woman sitting in the last seat is Nancy Jones, M.D. (Not M.D..)
Bring cookies, candy, potatoes, etc. I will bring the rest. (Not etc..)
When should I use a comma in a sentence?
A comma is a form of punctuation used to separate independent clauses, phrases and words in a sentence.
Examples: Bring cookies, candy, potatoes, etc. I will bring the rest.
A car travels at a very fast speed, but a plane travels faster.