Quotation Marks and Guillemets
In the United States, double quotes open and close a quotation. A quote within that quotation is opened and closed with single quotes. The left quotes look like two little sixes (6), while the right quotes look like little nines (9).
In Great Britain, single quotes open and close a quotation. A quote within that quotation is opened and closed with double quotes.
In Germany, double quotes on the baseline open quotations, and a single quote on the baseline signifies the opening of another quotation within it. The single and double opening quotation marks look like little nines (9). Right quotes resembling sixes (6) close the quotations.
In certain parts of the world, guillemets may be used to set quotations. In Germany and Austria, quotations are opened with right-facing double guillemets, and closed with left-facing double guillemets. Quotes within quotations are marked with single guillemets.
Swiss German typographers set guillemets differently. Quotations are opened with left-facing double guillemets, and closed with right-facing double guillemets. Quotes within quotations are opened with left-facing single guillemets, and closed with right-facing single guillemets.
French typographers traditionally place a small amount of additional space between the guillemets and the text inside them.