1.	Use a comma between the day of the week and the month-date.
I will be there on Monday, December 25.
2.	Use a comma  to separate two or more items in a sentence.
I love boxing, my family and my dog. 
3.	Use a comma between the name of a city and the state.
I was born in Woodbridge, Suffolk.
4.	Use a comma after introductory words like yes / no / wow / hey.
Wow, we won the match!
5.	Use a comma to separate the name of a person in a direct address.
Harry, what happened to you? / What happened to you, Harry?