If you are using less than four lines, it depends on whhteer the section is in iambic pentameter or blank verse. You can often tell by whhteer the first letter of each line is capitalized or not. If it is, you cite it as poetry, like so: “If by your art, my dearest father, you have/ Put the wild waters in this roar, allay them” (I.II 1-2). If the lines are in blank verse, you cite them as you would any other source. In other words, you do not use the slash that indicates the end of a line of poetry. In both cases, the numbers at the end indicate Act/Scene number (Roman numerals) and the line numbers. If it is more than four lines long, you use a block quote.