Apostrophe has only one name. It's apostrophe. The plural is apostrophes.
Only use apostrophes in contractions, and to show possession
They can. Many names of Irish origin have an apostrophe like O'Brien or O'Berry.
Yes
That is the correct spelling of "apostrophe" (the punctuation mark ' ).
He was researching where the correct place to put apostrophes is.
Plurals don't use apostrophes, so the first one is correct.
Some email providers allow apostrophes in email addresses to accommodate users with names that contain apostrophes. It helps ensure that individuals with such names can create email addresses that accurately reflect their identities.
pros and cons is the correct noun
The correct placement of apostrophes in your sentence would be: "Mike's brother's friend's cousin did a brilliant project on Saturn's moons." The apostrophes indicate possession for Mike (his brother), his brother (his friend), and the moons belonging to Saturn.
Grammatically, Presidents' Day is NOT correct. The correct spelling should have no apostrophes at all as the day does not BELONG to the presidents, therefore it is not possessive.
The Johnsons No apostrophes needed anywhere.
The correct sentence is "Amber's antique book from 1879 is missing."