And when when did you this, explain how to use an apostrophe to show possession for singular and plural noun to form contractions

I can help explain how to use an apostrophe to show possession for both singular and plural nouns and to form contractions.

1. Apostrophe to Show Possession:
a) Singular noun: To show possession for a singular noun, add an apostrophe followed by an "s" at the end of the word. For example:
- The cat's toy
- Sarah's book
- The car's engine

b) Plural noun: To show possession for a plural noun that already ends in "s," simply add an apostrophe after the "s." For example:
- The teachers' lounge
- The dogs' leashes
- The cars' windshields

*Note: If the plural noun does not end in "s," add an apostrophe followed by an "s" like with singular nouns. For example:
- Children's toys
- Women's shoes
- Men's hats

2. Apostrophe to Form Contractions:
Contractions are formed by combining two words and replacing one or more letters with an apostrophe. Here are examples of commonly used contractions:
- I am → I'm
- Do not → Don't
- It is → It's
- She has → She's
- They are → They're

*Note: Be careful not to confuse contractions with possessive pronouns (e.g., its, yours, ours), which do not use apostrophes.

Remember to use an apostrophe correctly to avoid any grammatical errors or confusion in your writing.