Q. Please help. I have confusion regarding the correct spacing after periods and other closing punctuation. My company uses
the font Arial and consistently uses a flush-left margin. We are an engineering company. My job consists in preparing documents
and letters for customers. Everything I read in manuals and from technical writers directs me to use one space after periods.
I find that it works very well, except occasionally, when an extra space helps readability. Knowledgeable engineers have embraced
the one space use as being consistent with the font design and automation of reports. Others are unpleased with the one space,
they think they have difficulty reading. (I, too, had an adjustment period which I forced myself to endure until it became
automatic to read easily.) We are preparing technical information. What do you think? Thanks for your wonderful support and
especially the quick answers. I greatly appreciate your service.
A. The view at CMOS is that there is no reason for two spaces after a period in published work. Some people, however—my colleagues included—prefer it, relegating this
preference to their personal correspondence and notes. I’ve noticed in old American books printed in
the few decades before and after the turn of the last century (ca. 1870–1930 at least) that there seemed
to be a trend in publishing to use extra space (sometimes quite a bit of it) after periods. And many people were taught to
use that extra space in typing class (I was). But introducing two spaces after the period causes problems: (1) it is inefficient,
requiring an extra keystroke for every sentence; (2) even if a program is set to automatically put an extra space after a
period, such automation is never foolproof; (3) there is no proof that an extra space actually improves readability—as
your comment suggests, it’s probably just a matter of familiarity (Who knows? perhaps it’s
actually more efficient to read with less regard for sentences as individual units of thought—many centuries
ago, for example in ancient Greece, there were no spaces even between words, and no punctuation); (4) two spaces are harder
to control for than one in electronic documents (I find that the earmark of a document that imposes a two-space rule is a
smattering of instances of both three spaces and one space after a period, and two spaces in the middle of sentences); and
(5) two spaces can cause problems with line breaks in certain programs.
So, in our efficient, modern world, I think there is no room for two spaces after a period. In the opinion of this particular
copyeditor, this is a good thing.
Q. Help. How many spaces do you leave after a colon in a manuscript?
A. One space after a colon. There is a traditional American practice, favored by some, of leaving two spaces after colons and
periods. This practice is discouraged by the University of Chicago Press, especially for formally published works and the
manuscripts from which they are published.
Q. About two spaces after a period. As a US Marine, I know that what’s right is right and you are wrong.
I declare it once and for all aesthetically more appealing to have two spaces after a period. If you refuse to alter your
bullheadedness, I will petition the commandant to allow me to take one Marine detail to conquer your organization and impose
my rule. Thou shalt place two spaces after a period. Period. Semper Fidelis.
A. As a US Marine, you’re probably an expert at something, but I’m afraid it’s
not this. Status quo.
Chicago Style Q&A: New Questions and Answers
