The possessive of a singular noun is formed by adding an apostrophe ( ' ) and the letter -s.

Examples:

• The farmer's plow

• Our teacher's plan

The possessive of a plural noun is formed by adding an apostrophe ( ' ) after the -s.

Examples:

• the teachers' lounge

• the students' classroom

The possessive of a plural noun that does not end in -s is formed by adding an apostrophe ( ' ) and -s.

Examples:

• children's laughter

• women's league

The possessive of a proper noun that ends in -s or -z is formed by adding an apostrophe ( ' ) and -s.

Examples:

• Charles's project

• Maris's song

The possessive of a proper noun from classical literature or ancient times that ends in -s is formed by adding an apostrophe ( ' ) after the -s.

Examples:

• Moses' rod

• Jesus' parable

The possessive of a compound noun is formed by adding an apostrophe ( ' ) and -s to the last word.

Examples:

• my daughter-in-law's dress

• managing editor's report

The possessive of a pair of nouns that denote individual ownership is formed by adding an apostrophe ( ' ) and -s to both the nouns.

Examples:

• Lucy's and Sheena's projects

• Kate's and Ernie's dogs

In a pair of nouns that denote collective or joint ownership, the second word takes the possessive form.

Examples:

• Anna and Gina's parents

• Father and mother's decision

Inanimate objects, ideas, and qualities usually use the of-phrase to show possession.

Examples:

• the leaves of the trees

• the arms of the chairs

However, some idiomatic expressions are considered exception to the above guidelines and can show possession by adding an apostrophe ( ' ) and -s to the noun.

Examples:

• a day's work

• journey's end

• the earth's surface