Apostrophe
The Apostrophe is used when showing possessive, when letters are omitted, and for plurals of letters.
Possessive
Either in British or American, or other English speaking/writing usage, the possessive plural use of apostrophes an 's' depends on whether
a) the original singular form ends in an 's' and
b) the plural form requires adding an 's' and then needs an apostrophe to show possessive and if you create the 'esses' sound at the end.
St. James is a singular noun with an 's' ending. Hence, add an apostrophe s for the possessive with an 'es ses' pronunciation: St. James's and you pronounce it 'Saint James es.'
The same would be true of 'bus' or bus's. Pronounce it bus es.
Girl is a singular form of a noun because an 's' has been added to make it plural. It's not a part of the original word. If you wish to show possessive, add an apostrophe s: girl's. Pronounced girlz.
Men is a plural form of a noun without an 's' ending. If you wish to show possessive, add an apostrophe s: men's. Pronounced menz.
Girls is the plural form of the noun. If you wish to show possessive, add an apostrophe and leave off the additional 's' because you don't want it to say 'girl es ses,' but 'girlz' hence: girls' and not girls's.
Letters are Omitted
Contractions:
Are not - aren't
Cannot - can't
Could not - couldn't
Do not - don't
Have not - haven't
I am - I'm
It is - It's
Must not - Mustn't
S/he is - s/he's
They are - They're
You are - You're
We are - We're
We were - We're
Omitted Letters in words:
Dropped ending letter when showing vernacular:
Goin' - going
Funnin' - funning
Fixin' - fixing
Yon' - yonder
Letters in the middle of words omitted in common usage:
E're - Ever
'til - until
Fo'c's'le - forecastle
Bo's'n - Boatswain
When writing plurals of letters:
P's and Q's
ABC's
X's
Y's
Z's
Either in British or American, or other English speaking/writing usage, the possessive plural use of apostrophes an 's' depends on whether
a) the original singular form ends in an 's' and
b) the plural form requires adding an 's' and then needs an apostrophe to show possessive and if you create the 'esses' sound at the end.
St. James is a singular noun with an 's' ending. Hence, add an apostrophe s for the possessive with an 'es ses' pronunciation: St. James's and you pronounce it 'Saint James es.'
The same would be true of 'bus' or bus's. Pronounce it bus es.
Girl is a singular form of a noun because an 's' has been added to make it plural. It's not a part of the original word. If you wish to show possessive, add an apostrophe s: girl's. Pronounced girlz.
Men is a plural form of a noun without an 's' ending. If you wish to show possessive, add an apostrophe s: men's. Pronounced menz.
Girls is the plural form of the noun. If you wish to show possessive, add an apostrophe and leave off the additional 's' because you don't want it to say 'girl es ses,' but 'girlz' hence: girls' and not girls's.
Letters are Omitted
Contractions:
Are not - aren't
Cannot - can't
Could not - couldn't
Do not - don't
Have not - haven't
I am - I'm
It is - It's
Must not - Mustn't
S/he is - s/he's
They are - They're
You are - You're
We are - We're
We were - We're
Omitted Letters in words:
Dropped ending letter when showing vernacular:
Goin' - going
Funnin' - funning
Fixin' - fixing
Yon' - yonder
Letters in the middle of words omitted in common usage:
E're - Ever
'til - until
Fo'c's'le - forecastle
Bo's'n - Boatswain
When writing plurals of letters:
P's and Q's
ABC's
X's
Y's
Z's