I have a doubt!

- How many ears have the dog? Incorrect
- How many ears does the dog have? Correct
Are these sentences right?

 

About the first sentence, I'd like to point out that (even though the structure of the question is incorrect) when talking about a single thing aka not attaching the 's', you must use 'has'. Have is used with plurality.

 • The DOG HAS two ears.

 • The DOGS HAVE two ears.

 When it comes to such sentences, I mastered them knowing I shouldn't use more than one 's'.

 • How many ears DOES THE DOG have?

 • How many ears DO THE DOGS have?

 I just wanted to point this out, even though it wasn't the point of your question, just in case if you struggle with it :D

I have a doubt!

- How many ears dog have?
- How many ears does the dog have?
Are these sentences right?

I have a doubt!

- How many ears have the dog?- Incorrect
- How many ears does the dog have? correct
Are these sentences right?