Answer:
There are no general rules about such functions, the student or critic analysing the poem has to decide in each case afresh which is the function in the particular poem he or she is dealing with.
Step-by-step explanation:
Two aspects of stanza form are particularly relevant for the analysis of poetry: First, a stanza form is always used to some purpose, it serves a specific function in each poem. Second, well-known stanza forms stand in a certain tradition. The sonnet for instance started its career in English poetry as a love poem.