The first line of the play is Antonio saying, "In sooth I know not why I am so sad." In a small way, the repetition of the S sound ("so sad") lends a sense of degree.
In Act 2, Scene 4, Lorenzo gives Launcelot instructions to "Tell gentle Jessica / I will not fail her" (lines 19-20). The initial sounds don't change very much from gentle to Jessica (the g/J and e are the same in both words), and the smoothness involved in moving from one to the other matches the meaning of "gentle."
