Aside
A short speech or remark given by a character, which is supposed to be unheard by other characters on the stage.
Soliloquy
A speech delivered by a character alone on the stage, and the characters able to talk to themselves. Also used to inform the audience of the character state of mind.
Chorus
A character or group of characters who give comments on the play which link acts or foreshadow coming events.
Pathos
A quality that evokes, pity or sadness.