In John Keats's ode "To Autumn," in what way can the stanzas be distinguished by the type of discourse addressed to the season?
As your question presupposes, there are different types of discourse going on in this poem. In the first stanza, the speaker is merely describing autumn, and he uses a great deal of physical, visual imagery to paint a picture of the season. In the second stanza, however, the speaker moves from talking about autumn to actually talking to autumn, personified as a farm worker at harvest-time. When a poet or speaker addresses or speaks to an entity that really isn't capable of responding (such as an inanimate object or an abstract idea), it is called apostrophe. In the third stanza, Keats continues his use of apostrophe; however, the third stanza almost acts as a synthesis of the previous two stanzas, in that Keats carries over the apostrophe of the second stanza but combines it with rich imagery reminiscent of the first. In the third stanza, however, the imagery is auditory--we hear the birds chirping and the sheep lowing. So, the stanzas can be separated in terms of their usage of imagery as well as their usage of apostrophe.