Apostrophes can be used to show possession, to form contractions and to create plurals. When you use the apostrophe to show possession, add an apostrophe plus the letter 's' to show possession with a singular noun and irregular plurals (those not ending in 's'), a 's' should be added to the end of the word. For plural nouns ending in 's', only an apostrophe should be added.

Apostrophes

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"A woman's handbag is an important fashion item." "My friend's house is built on a hill." "My boss's wife is a pleasant person." "A dog's bark," "The people's transport," "An old wife's tale."
Just add an apostrophe for words ending in 's' which are the same in the singular as it is in the plural, e.g., a pair of scissors, two pairs of scissors',
There are many common nouns ending in the letter 's'; e.g., abscess, abyss, across, address, assess, boss, confess, express, less, moss, cypress etc.

Match Contractions to the correct word pairs

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Apostrophes used to form Contractions

The Apostrophe [']: This is used to show that a letter has been left out. e.g., won't (will not), can't (cannot; contrast cant), ***ne'er (never), o'er (over) it's (it is; contrast its, the possessive case of it).
When words are shortened by excluding one or more letters, apostrophes are used to form contractions. Contractions would rarely show up in formal writing, but a well-placed one here an there could have a positive effect
It is as contractions: The word it's is not a possessive form of it. The word it's serve as the contraction of the two words it is.
It is cold outside - It's cold outside
It is a very expensive watch. It's a very expensive watch
It is going to rain today. It's going to rain today. And, you are, you're; madam - ma'am; telling - tellin'; until - 'til. When apostrophes are at the beginning of a word as in 'til, make sure that the punctuation mark should look like a single closing quotation mark and not an opening one.

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It is also used to form the possessive case of nouns. The apostrophe with s ('s) forms the possessive case of all nouns, singular and plural, except plural nouns ending in s. These form the possessive case by adding the apostrophe only.
Examples: man's lot, men's clothes, Jones's house, with the two elder Joneses' dog, a lady's voice, ladies' waiting-room, a girl's step, a girls' school, this cap is John's.

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The possessive case of pronouns has no apostrophe, e.g. Yours truly. It's hers, it's theirs, the table cannot move its legs.
It is a pronoun and does not get an apostrophe. Just as the pronoun she has the possessive form of she and he the possessive form of his, the pronoun it has a possessive form as well: its. E.g., "The council published its new fees in the Government Gazette. The generator lost its power. The cat lost its eye in a fight. The dog chased its tail.

Rules for Plurals

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Apostrophe used to form the plural

The apostrophe is also used to form the plural of the name of any letter or figure, e.g., Mind your p's and q's. Dot your i's and cross your t's. How many 4's are there in 24?

Note that the apostrophe is not used, as in Afrikaans, to form the plural of foreign nouns ending in a vowel, e.g., arias, solos, emus (contrast Afrikaans, aria's, solo's, emu's).

Source: EBH Joubert: English Grammar
https://www.grammarbook.com/punctuation/apostro.asp
https://www.logicofenglish.com/spelling-lists/by-phonogram/298-english-words-ending-is-ss

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