Adjectives are descriptive words that describe other words and answer a question.
Thus, in your sentence, the adjective is the word red, as is tells the reader what color the shirt is.
Yes. I think people should limit their cellphone use. I think this because there is a whole world to experience and everyone is on their phones instead. phones are so dangerous to society. 80% of car accidents are caused by cell phone use while driving. I think cell phones need to be limited.
A child's oral vocabulary is closely related to some forms of poetry depending on the age.
I presume this is from Lewis Carol's nonsense poem "Jabberwocky," when he uses the phrases "vorpal" it means deadly. A deadly sword.