Read the full text of Love's Labour's Lost Act 3 Scene 1 with a side-by-side translation HERE.
Armado finally gets that song out of Moth. He plans to release Costard to carry his love note to Jaquenetta. Moth teases his hapless master about his love and how he plans to win it. Armado sends him to fetch Costard.
Costard has a broken shin and is starving. He confuses "l'envoy" (the conclusion of a piece of writing) with salve for his broken leg. This cracks Armado up and gives him an opportunity to show off his superior learning. Moth gets in on the action.
Finally Armado gets to the point: he'll free Costard to take a letter to Jaquenetta. He does it and gives him a little money. Armado and Moth exit.
Berowne enters. Costard asks how much ribbon he can buy with the three farthings Armado gave him. Berowne clearly has no idea, which Costard takes as an answer. But not so fast.
Berowne has an errand for the peasant. Take this letter and find Rosaline. He gives Costard money, too.
After Costard's exit, Berowne has a long monologue expressing his amazement that he—always so cynical about love—has fallen for a girl "with two pitch balls stuck in her face." Oh Berowne. That's the way to woo 'em.