Some differences between demonstrative and argumentative speeches is that a demonstrative speech is when you show or demonstrate to someone how to do something. While an argumentative speech aims to change your audience's view or perspective of something. A demonstrative speech is also meant to teach someone something, while an argumentative speech is meant to persuade. Argumentative essays also need to be backed up with facts and/or data. They are similar because they both lead the audience to learning something new. They inform the audience on something. Hope that helps.
