Defining
Person:
The neightbour who lives across the next street is moving next moth
Thing:
I left the book that you lent me at home
Place:
That´s the restaurant where my parents had their first date
Possesion:
Do you know anyone whose birthday is chrismas day?
Undefining
Person:
My neighbor, who has a swimming pool, has invited us for a barbecue tomorrow
Thing:
The book, wich i read in under a week, was fascinating.
Place:
The restaurant, where you can eat foods from all over the word, is quite expensive
Possesion:
Tommy, whose birthday falls on december 25, complains he never gets enough presents.
We use them to combine sentences without repeating information
Defining
Give essential information about the person or thing they drescribe
Example:
*She is the girl who stole my lunch.
Undefining
Are separeted by commas and give additional information
Example:
Jane is usually friendly and kind