one space between sentences

Always one—never two

Some top­ics in this book will offer you choices. Not this one.

Always put exactly one space between sen­tences.

Or more gen­er­ally: put exactly one space after any punc­tu­a­tion.

Here’s a para­graph with one space between sen­tences:

I know that many peo­ple were taught to put two spaces between sen­tences. I was too. But these days, using two spaces is an obso­lete habit. Some say the habit orig­i­nated in the type­writer era. Oth­ers believe it began ear­lier. But guess what? It doesn’t mat­ter. Because either way, it’s not part of today’s typo­graphic prac­tice. If you have to use a type­writer- style font, you can use two spaces after sen­tences. (These are also known as monospaced fonts.) Oth­er­wise, don’t.

Now the same para­graph, but with two spaces between sen­tences:

I know that many peo­ple were taught to put two spaces between sen­tences.  I was too.  But these days, using two spaces is an obso­lete habit.  Some say the habit orig­i­nated in the type­writer era.  Oth­ers believe it began ear­lier.  But guess what?  It doesn’t mat­ter.  Because either way, it’s not part of today’s typo­graphic prac­tice.  If you have to use a type­writer-style font, you can use two spaces after sen­tences.  (These are also known as monospaced fonts.)  Oth­er­wise, don’t.

I could tell you that in the sec­ond para­graph, the extra spaces dis­rupt the bal­ance of white space. I could warn you that mul­ti­plied across a whole page,rivers” of white space can appear. But mostly, one space is the well-set­tled cus­tom of pro­fes­sional typog­ra­phers. You don’t need to like it. You only need to accept it.

I have no idea why so many writ­ers resist the one-space rule. If you’re skep­ti­cal, pick up any book, news­pa­per, or mag­a­zine and tell me how many spaces there are between sen­tences

Cor­rect—one.