Would you say my home country my home country is very beautiful? No, of course you wouldn’t. So, don’t repeat the subject in a sentence.
- I have some melons they are green.
(Melons and they are the same subject, so this sentence is wrong.) - I have some green melons.
- The duck it is on my car.
(Duck and it are the same subject, so this sentence is wrong.) - The duck is on my car.