Kitty Cat. Puppy Dog. Doll Baby. Tuna Fish

[Bunny]

Why do we use compound nouns to refer to something, when we really only need one word?

Kitty.
Puppy.
Doll.
Tuna.

See? Same object, only one word. Or am I the only one who does this?
Do you know of any others like this? And is there such a thing as a compound noun, or did I make that up?

[Nevernose]

1. Your second teo examples:

It's to demonstrate the type of object. What kind of fish? A tuna fish. What kind of doll? A baby doll.

And why do we say "kitty cat" or "puppy dog?" 'Cuz it sounds cute when three year olds do it.

[Bunny]

2. But isn't tuna always a fish?

If you are asked what you had for lunch today and said tuna, would the questioner wonder if you had tuna beef, or tuna chicken? (Well, if they were Jessica Simpson they may wonder about the chicken!)

I see your point, it just seems comically redundant to me. And I say them all the time.

[Richardo]

3. Until they're house trained, I call them "poopy dogs"

...and I don't care WHO it annoys. :evilgrin:

[Bunny]

4. That's so funny!

I'm in the process of housebreaking my "poopy" right now. We are into Day Eight of the process, and she still has NO clue what she's being asked to do!

[geniph]

6. Remember, little poopies

don't have much control of their bowels or bladder before they're four months old or so - so they literally can't hold it before then. You just have to live with some accidents until their control of the muscles catch up.

I love other people's puppies...because I don't have to clean up the poopies!

[qb]

5. I sometimes get annoyed when my wife says "tuna fish"

It's just plain redundant!! However, I say "puppy dog" and "kitty cat" all the time. I guess it's time to lighten up! Thanks for the insight.