Periods and commas belong inside quotes in American English

Published on in English

Like so: "The name's Bourne," the man said, "JSON Bourne." Also when quoting single words, like "nibbles," "gronk" and "fleebles."

Why? Because it's a rule. Some sources:

If you are not convinced, consult your favorite style guide.

I write mainly American English. I avoid mixing in other flavors, like British English, to keep my English consistent.

An exception to the rule

Place periods and commas outside the quotes if placing them inside the quotes could make the text ambiguous or lead to errors, e.g. when quoting user inputs.

For example:

The password is "hunter2."

The above is ambiguous: does the password include the period or not?

Compare with this:

The password is "hunter2".

The above is unambiguous and thus preferable.

Sometimes it's better to change the sentence structure to avoid this problem.

I don't know if this exception is actually allowed in American English, but it's common sense.