Writing Tips has been archived and won’t be updated before it is permanently deleted.
For the most up-to-date content, please consult Writing Tips Plus, which combines content from Writing Tips and The Canadian Style. And don’t forget to update your bookmarks!
Follow the guidelines below to form the plural of different types of abbreviations.
Add an s, but not an apostrophe, to form the plural of most abbreviations:
Add an s without an apostrophe to form the plural of abbreviations with only one period. The s is added before the period:
In cases where the resulting form would be ambiguous, add an apostrophe before the s:
Add an apostrophe and s to form the plural of abbreviations containing more than one period:
Use an apostrophe and s to form the plural of numerical names of aircraft ending in a single letter:
The plurals of Mr. and Mrs. are irregular:
The plural forms of the abbreviations for certain bibliographic references are different:
Singular | Plural |
---|---|
l. (line) | ll. |
p. (page) | pp. |
f. (and the one following) | ff. |
c., ch. (chapter) | c., ch. |
MS (manuscript) | MSS |
but | Plural |
s. (section) | ss. |
subs. (subsection) | subss. |
Note that SI/metric symbols maintain the same form for both singular and plural and are written without periods, except at the end of a sentence:
© Public Services and Procurement Canada, 2024
TERMIUM Plus®, the Government of Canada's terminology and linguistic data bank
Writing tools – Writing Tips
A product of the Translation Bureau