lowercase letters ... form the plural with an apostrophe and an s". The Oxford Style Manual on page 116 advocates the use of common sense.
us
det
The speakers/writers, or the speaker/writer and at least one other person.
pron
Me.
Our.
Me and at least one other person; the objective case of we.
Me (in all contexts).
How often have the words lowercase letters ... form the plural with an apostrophe and an s". The Oxford Style Manual on page 116 advocates the use of common sense. and us occurred in a corpus of books? (source: Google Ngram Viewer )