monologue
A speech by one person is called a monologue.
A form of speech with only one person speaking is called a monologue.
soliloquy pronounced (sa-lil-o-quee)
Speech Monologue An orderly meeting
I know the study is called linguistics, but I don't know what the person is called.
The person who gives a speech is called a speaker or an orator. They are responsible for delivering a message or addressing a topic to an audience.
That is called a metonymy. It is a figure of speech where one term is substituted with another term that is closely related or associated with it.
I think you are talking about a soliloquy.
A monologue is a speech, usually a long speech, by one person.
A word from a text or speech spoken by another person is typically referred to as a quotation or a quote.
It is called quoting (or to quote) the person and you should do also giving acknowledgement to the person and in which work he wrote it.
It's called a monologue. A dialogue is two or more. If the character is talking to his/her self then it is called a soliloquy. An example is Hamlet's soliloquy "To be or not to be that is the question ........."