posted by rfvv .
1. She likes playing with her dog.
2. She likes playing with a puppy.
3. She likes playing with her puppy.
4. She likes playing with puppies.
(Which expression is commonly used?)
5. Why do people call New York the Big Apple?
6. Why do people call Chicago the Windy City?
#1 - 4. Decide if it's a dog (age 4, 5, for example) or a puppy (up to 8 months to a year old) for the difference between 1 & 3. As for #4, there is more than one. You could use any one of those expressions, depending upon the context.
5. I often wondered myself. Perhaps it is/was "the apple of someone's eye" but the following link entertains other reasons: http://gonyc.about.com/cs/atozinde1/a/bigapple.htm
6. I'm not researching this one because I remember standing on a street corner and nearly blowing away from the wind from the lake!