If it's one Aussie - the word is Aussie's - as in "The Aussie's dropped he ball again". If it's more than one Aussie - the apostrophe is 'implied' - as in "The Aussies lost again"
Aussies's can have an apostrophe but there shouldn't be an s after the apostrophe.
Aussie's is the possessive singular form of Aussie. eg The Aussie's dog is missing. - here - 's - shows the dog belongs to the Aussie (one Aussie).
Aussies is the plural form of Aussie and means more than one. eg The Aussies lost the game.
Aussies' is the plural possessive form of Aussie. eg The Aussies' fullback was hopeless.
There is no implied apostrophe.
I am does not need an apostrophe. It is only when you make it into a contraction by dropping the a that you need the apostrophe. It becomes I'm in that situation.
No. The Cannons doesn't need an apostrophe.
No, Christmas Eve does not need an apostrophe.
No, because plurals do not need an apostrophe.
As a plural, for more than one dad; no, does not need an apostrophe. As a possessive, as in the item belonging to dad, then yes, it does need an apostrophe.
No. Harringtons doesn't need an apostrophe.
The plural "Thursdays" doesn't need an apostrophe.
Lost wages doesn't need an apostrophe.
No, "Doc Adams" does not need an apostrophe unless it is possessive, such as "Doc Adams's bag."
do you need an apostrophe after the s in Koreans
No you don't! Horses does not need an apostrophe.
No, ours does not need an apostrophe (ever).The piano at the church had been ours.