Distinguish between Rosalind's healthy humor, Touchstone's professional humor, Jaques' satirical humor, and Corin's natural humor?
Rosalind's humor is "healthy" in that it is compassionate. It pokes fun, gently, at the foibles of human nature, particularly those of men and women in love. She can even make fun of herself, as when she says to Celia, "Do you not know I am a woman? When I think, I must speak" (act III, scene 2, lines 247-248). Her humor, though empathetic, is practical: "Men have died from time to time, and worms have eaten them, but not for love" (IV,1,ll.101-102). When she outduels Jaques (IV,1), there is a sense that, in doing so, she is being as kind as possible about it. Regarding his vaunted "experience," she remarks, "I had rather have a fool to make me merry than experience to make me sad" (ll.25-27). The greater part of Rosalind's wit is found in the two scenes (III,2 and IV,1) in which she impersonates a young man in order to "woo" Orlando. This wit takes many forms, but it is always rooted in her passion, need, desire and sympathy for her lover.
Touchstone's humor is "professional" chiefly because he is, of course, a professional humorist - a court jester. He is more than able to zing a quip here and there: When Rosalind says, "O Jupiter! How weary are my spirits!," he responds, "I care not for my spirits if my legs were not weary" (II,4,ll.2-3). When she refers to Orlando's verses to her, saying "I found them on a tree," he retorts, "Truly, the tree yields bad fruit" (III,2,ll.115-116). Much of Touchstone's humor, however, comes in the form of monologues, speeches so witty and complete they seem to be rehearsed "party pieces." Three clear examples of these comic tirades are his bit about being in love with "Jane Smile" (II,4,ll.44-54), his parody of Orlando's poems to Rosalind (III,2,ll.100-112), and his dazzling discourse "Upon a lie seven times removed" (V,4,ll.69-103). As a professional, Touchstone has a comic monologue ready for almost any occasion.
As funny as Touchstone is, however, he cannot get the best of Corin. In fact, in act III, scene 2 (ll.11-69), the shepherd seems to out-jest the jester. In a sinuous argument in which the court clown attempts to trap Corin and make him look foolish, the latter trips up the former, "hoisting him by his own petard." In making Touchstone assert that "civet is of a baser birth than tar," Corin makes him admit that the "shepherd's life" is superior to that of the court. Corin doesn't manipulate towards this end; he simply states what he knows to be true and watches as his motley friend hangs himself. He is not at all the "natural" that Touchstone takes him for.
The humor of Jaques is, perhaps, the most complicated. Although he is primarily associated with "melancholy," he is ripe with sharp wit - not as polished, perhaps, as that of Touchstone; certainly not as kind as that of Rosalind. When the singer says to him, "My voice is ragged, I know I cannot please you," Jaques quips, "I do not desire you to please me, I do desire you to sing" (II,5,ll.13-15). After using a strange word to gather his mates around him, one of them asks, "What's that 'ducdame'?" - to which Jaques replies, "'Tis a Greek invocation, to call fools into a circle" (II,5,ll.52-54). One of the most unique moments in the play (and, perhaps, in Shakespeare) is when, in act IV, scene 1 (ll.28-30), Orlando says, "Good day and happiness, dear Rosalind," and Jaques exits, saying, "Nay, then, God be with you an [if] you talk in blank verse."