Yes. Wales is a nation and a non-sovereign country located on the island of Great Britain.
Lady Sovereign is from England.
North Korea thinks that it is Sovereign. But they are not.
Yes
Canada is an independent country.
China is not in any country. It is a sovereign country in its own right.
One of the many definitions of "Sovereign" is, the reigning Monarch of a country. Englands current Sovereign is Queen Elizabeth II.
None. Bulgaria is a sovereign country itself.
It is an independent sovereign state.
Italy is a sovereign country.
A sovereign state.
Generally, "constituent country" is a term applied to territories that call themselves countries, that are a part of a bigger sovereign country. For example, England is a constituent country of the United Kingdom and Greenland is a constituent country of the Kingdom of Denmark. If you mean a sovereign country within another sovereign country, that is called an enclave.