The copyright to the work refers to the work both in its original form and when it is available in an altered form, like a translation or adaptation.
To be able to make a translation or adaptation of a copyright protected work available to the public, authorisation from the rights owner is required. Translation means the expression of a work in a language other than that of the original version.
Adaptation is generally understood as the modification of a work to create another work, for example adapting a novel to make a film; or the modification of a work for different conditions of exploitation, e.g., by adapting a textbook originally written for university students to make it suitable for a lower level.
However, a person who has translated or adapted a work or converted it into some other literary or artistic form have copyright in the work in the new form but have no right to control it in a manner which infringes the copyright to the original work.
If a person, however, in free connection with a work, has created a new and independent work, his or her copyright is not subject to the right in the original work. To have a work as inspiration when you create a new independent work is allowed.