title_body: How could a conlang enforce subjective idealism in a constructed world
upvoted_answer: You may be interested in E-Prime.  
  
  E-Prime is a version of English that excludes all forms of the verb to be, including all conjugations, contractions and archaic forms. This makes many objective statements like "Roses are red" impossible. Instead a person is required to use more subjective constructions like "Roses appear red to me".