The copyright holder and his or her agent, representative, or licensee.
how should you show that a piece nof work is copyrighted
Only if the copyright is not part of the copyright registration that is copyrighted in the publication of the author's registration. But If the copyright is part of the copyright registration that is copyrighted in the publication then the copyrighted author of which publicized the copyrighted registration is not copyrighted in the legalized sense of which a publication is copyrighted. Yes, a work is always copyrighted, before and after editing and both versions.
Anything new that someone writes can be copyrighted. Technically a work is automatically copyrighted once it is created unless the author explicitly abandons copyright in the work.
Your can publish or create anything you want as long as it isn't copyrighted or plagiarized.
You can't copyright anything that isn't your original work. But since copyright is automatic, if something is copyrightable and it exists, it is protected. That is, there is nothing in existence that is copyrightable that is not copyrighted.
No; the act of changing it would be infringing on the creators exclusive right to alter the work and create derivatives.
No, not without permission. One of the rights that copyright conveys is right to display the work publicly. By placing the copyrighted work in your portfolio, everytime you show it you are usurping the original artists right.
It is okay to write a book on something that is copyrighted, but you cannot publish your work unless you get permission from the author.
Permits the use of copyrighted work.
The entire novel is copyrighted. While one cannot technically copyright a title, the book is a copyrighted work. The holder can bring suit against anyone that violates their rights.
The only way a work created by you can become 'not' copyrighted, is if you've voluntarily given up those rights.
Ideas are not subject to copyright protection; only the expression of the ideas.