Final answer:
When quoting longer than four lines of prose, it should be indented and formatted as a block quote, without quotation marks unless there is a quote within a quote. This gives clear separation from the rest of the text.
Step-by-step explanation:
When a quote is longer than four typed lines of prose, it should be indented. This is known as a block quote. Block quotations are formatted by indenting them from the rest of the text but maintaining the same spacing as normal text. Unlike shorter quotations that are embedded within the main body of the paper and enclosed in quotation marks, block quotations do not require quotation marks unless there is a quotation within the quotation.
Block quotations should be used sparingly, and primarily when you need to present substantial evidence or a large portion of text for analysis. When following MLA style guidelines, for example, you should indent the block quotation one-half inch from the left margin. In the case of quoting more than three lines from a poem, you also indent the quotation without using quotation marks, with the period preceding the parenthetical citation.
In summary, use block format for direct quotations that are longer than four lines in prose or three lines in poetry. This method helps to clearly separate the quoted material from the rest of your text and provides a clear and professional presentation of longer quotations.