Romeo and Juliet Act 2

The scene I have chosen to write about is the scene with Romeo and Friar Larence. This scene is weird. Mostly beacause friar larence says that romeo doesn't really love juliet and they shouldn't be getting married and he goes on and on talking about that. but then, he says, "Ok, I'll merry you to juliet". What is he thinking? I know from the prologue that Romeo and Juliet's death bringspeace to Verona but how does he know.