When an abbreviation ending in a period such as etc., a.m., or p.m. appears within parentheses or brackets, place another period after the closing parenthesis or bracket. This period marks the end of the larger sentence to which the parenthetical text belongs.
- They sell confectionary (cakes, cookies, etc.).
- She wakes up early to write (at 4 a.m.).
- Farley missed the boat (it left without him at 6 p.m.).
- Portable floating devices save lives (see Dash et al.).
In such sentences, where the parenthetical text is part of a larger sentence, another period is necessary to end the surrounding sentence.
- Incorrect: She called me late at night (at around 1 a.m.)
Place a period after parentheses to end the sentence.Correct: She called me late at night (at around 1 a.m.).
No period after parentheses
If a sentence with an abbreviation like etc. is contained entirely within parentheses (or brackets, in British usage), don’t place another period after the closing parenthesis. The sentence has already ended within parentheses. Use just one period, not two.
- This is the best bakery in town. (You should try their cakes, cookies, etc.)
- She woke up earlier than usual. (The bell rang at 4 a.m.)
- Unsinkable floating devices are even safer. (We base our analysis on Dash et al.)
The general rule is that when an abbreviation ending in a period appears at the end of a sentence, you need just one period, not two.
- Incorrect: She woke up at 3 a.m..
Correct: She woke up at 3 a.m.
This same rule applies to sentences that end within parentheses.
- Incorrect: Her day starts early. (She wakes up at 3 a.m.).
Incorrect: Her day starts early. (She wakes up at 3 a.m..)
Correct: Her day starts early. (She wakes up at 3 a.m.)
With other punctuation like question marks and exclamation points, if the punctuation belongs to the larger sentence, it goes outside parentheses.
- Are you free tomorrow (before 4 p.m.)?
- The room was quite dirty (ants, cockroaches, etc.)!
However, if the question mark or exclamation point belongs to the sentence inside parentheses, it appears right after the period that belongs to the abbreviation.
- We can meet tomorrow. (How about 2 p.m.?)
- The room was infested (ants, cockroaches, etc.!), and we checked out as soon as we checked in.