Question

1. A dog is a faithful animal.
2. A dog is one faithful animal.
3. A dog is any faithful animal.
4. A dog is every faithful animal.
5. A faithful animal is a dog.
6. One faithful animal is a dog.
7. One faithful animal is one dog.
8. One faithful animal is any dog.
9. Any faithful animal is any dog.
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Does #1 mean #2? Does 'a' mean 'one'?
Is 'a faithful animal' is a generic noun phrase? Then, does #1 mean #3 or #4? Can we use such expressions?
What about #5? Does #5 mean #7 or #9 or any other thing?

Answer 1

Yes, “a” usually means one, but speaking about dogs in general, I’d use 1 and 5, and maybe 6. The others aren’t quite right.