Hamlet 1.3 Word Nerd: Vulgar

A French woman perceives Americans as vulgar, not due to crude language, but a lack of refinement. The term 'vulgar' originates from Latin, meaning common people. The video also discusses American friendliness, which some view as overly familiar, echoing Polonius's advice to Laertes.

In what way does the text describe the evolution of the word 'vulgar'?

What caution does Polonius give to Laertes, and how is it related to the French woman's view?