Possessive 's

The possessive 's (also called the Saxon genitive or genitive case) shows ownership or relationship between nouns. Mastering this form requires 3 core decisions — where to place the apostrophe, when to use 's versus of, and how to handle special cases like time expressions and compound nouns. This complete guide covers A1–B1 levels with online exercises and printable PDF worksheets, giving you clear rules, memorable examples, and targeted warnings for the most common errors:

The good news: the vast majority of possessives follow simple, predictable rules. The main challenge is apostrophe placement with plural nouns — but once you understand the decision process (singular vs regular plural vs irregular plural), forming possessives becomes automatic.

Note: This lesson focuses on possessive nouns — nouns that use 's to show ownership (Tom's car, the dog's tail). Don't confuse possessive nouns with possessive pronouns (my, your, his, her) or possessive adjectives — those are different grammatical categories. Also, remember that possessive 's is different from plural -s: "cats" (plural, no apostrophe) vs "cat's" (possessive, with apostrophe).

Basic Possessive 's — Singular Nouns

The foundation of the possessive system is simple: add 's to a singular noun to show it owns something.

Rule: For singular nouns (one person, one thing, one animal), always add 's — even if the noun already ends in -s:

Some style guides accept James' (apostrophe only) for names ending in -s, but James's is more common in modern English and always correct.

Examples in sentences:

• This is Maria's new dress.
• I borrowed my brother's laptop.
• The neighbour's garden is beautiful.
• We visited our grandmother's house.

👉 Practice Singular Possessives →

Whose Questions — Asking About Possession

Whose is the possessive question word. Use it to ask who owns something.

⚠️ Whose vs Who's — The Most Common Confusion

This is one of the most frequent errors in English writing:

How to test which one to use: Try replacing the word with "who is" or "who has". If it makes sense, use who's. If not, use whose.

• ❌ Who's car is this? → "Who is car is this?" ✗ (doesn't make sense)

• ✅ Whose car is this? ✓

• ❌ Whose coming to the party? → Asking about ownership of "coming"? ✗

• ✅ Who's coming to the party? → "Who is coming to the party?" ✓

👉 Practice Whose Questions →

Possessive Apostrophe with Plural Nouns — The Error Hot Zone

This is where most learners struggle. The key is understanding that apostrophe placement depends on whether the plural ends in -s or not.

⚠️ The Plural Possessive Trap

The most common error with possessives is adding 's to a plural noun that already ends in -s. This creates confusion with the singular form:

Rule 1: Regular Plurals (ending in -s) → Add ' Only

When a plural noun ends in -s, add only an apostrophe (no extra s):

Memory tip: If the word already ends in -s (because it's plural), don't add another s — just add the apostrophe.

Rule 2: Irregular Plurals (not ending in -s) → Add 's

Irregular plurals don't end in -s, so treat them like singular nouns and add 's:

If you're not familiar with irregular plurals (children, men, women, people, mice, sheep, deer, fish), review Plural Nouns first.

Rule 3: Names Ending in -s → Usually Add 's

For names that end in -s, the modern standard is to add 's:

Note: Some style guides accept Keats' (apostrophe only) for classical names, but Keats's is always correct and more consistent with the general rule.

Decision Flowchart for Apostrophe Placement

Is the owner singular or plural?
│
├─ SINGULAR → Add 's
│  Example: cat → cat's tail
│
└─ PLURAL → Does it end in -s?
   │
   ├─ YES (regular plural) → Add ' only
   │  Example: boys → boys' room
   │
   └─ NO (irregular plural) → Add 's
      Example: children → children's toys

👉 Practice Plural Possessives →

Saxon Genitive vs Of-Genitive — Choosing the Right Form

English has two ways to show possession: 's (Saxon genitive) and of (of-genitive). The choice depends mainly on whether the owner is animate (person/animal) or inanimate (thing).

When to Use 's (Saxon Genitive)

Use 's with:

1. People and animals:

2. Time expressions:

3. Places and organizations:

When to Use Of (Of-Genitive)

Use of with:

1. Inanimate objects and things:

2. Long or complex noun phrases:

• the opinion of the people I met at the conference ✓
• the people I met at the conference's opinion ✗ (awkward)

Comparison Table

Exception: Some common phrases use 's with things: the water's edge, the earth's surface, the sun's rays — these are fixed expressions.

👉 Practice 's vs Of →

Special Possessive Forms

Compound Nouns — Add 's to the Last Word

For compound nouns (words made from two or more parts), add 's to the last word:

⚠️ Don't say: mother's-in-law, mothers-in-law's (one person), brother-in-laws

Joint vs Separate Possession

When two people own something together, add 's only to the last name. When they own separate things, add 's to each name.

Joint possession (one shared thing):

Separate possession (different things):

Fixed Expressions — The Place Noun is Dropped

In some common expressions, we use 's but drop the place noun that follows:

👉 Practice Special Forms →

Advanced Possessives — Time Expressions & Double Genitive

Time Expressions Use Possessive 's

Time words and periods use the possessive form to show "belonging to that time":

Singular time expressions (one unit) → 's:

Plural time expressions (multiple units) → s':

Exception: When a time expression is used as a compound adjective before a noun, use a hyphen with no possessive:

• a three-day spa package (not three days' spa package)
• a two-week holiday (when used before a noun)
• BUT: We had two weeks' holiday. (when not directly before the noun it modifies)

Double Genitive — Of + Possessive 's

The double genitive uses both "of" and "'s" together. Use it to mean "one of [someone's] [things]":

Examples:

• That painting is a masterpiece of Monet's. (= one of Monet's masterpieces)
• I met a colleague of Sarah's at the party. (= one of Sarah's colleagues)
• This idea was a suggestion of Peter's. (= one of Peter's suggestions)

With pronouns: Use the possessive pronoun directly (no "of 's"):

• Is David a friend of yours? (not a friend of your's)
• That cousin of mine is coming to visit. (not of mine's)

👉 Practice Advanced Possessives →

Common Mistakes to Avoid

Quick Summary

4-Step Decision Process: How to Form the Possessive

Step 1: Identify ownership — Who or what owns something?

Step 2: Check noun type — Is the owner singular, regular plural, or irregular plural?

Step 3: Apply apostrophe rule:

• Singular → add 's (Tom → Tom's)
• Regular plural (ends in -s) → add ' only (boys → boys')
• Irregular plural (doesn't end in -s) → add 's (children → children's)

Step 4: Person vs thing? — If the owner is a thing (inanimate object), consider using of instead

• Person/animal → 's (my friend's house)
• Thing → of (the leg of the table)

Core Rules Quick Reference

Practice Tips

1. Master the apostrophe placement decision first The biggest challenge is knowing where to put the apostrophe. Practice the 3-way distinction: singular (add 's), regular plural ending in -s (add ' only), irregular plural not ending in -s (add 's). Once this becomes automatic, the rest is easy.

2. Learn 's vs of by category, not case-by-case Don't memorize individual examples. Instead, remember the categories: people/animals → use 's; things/places → use of. This single principle covers thousands of cases.

3. Watch out for whose vs who's in writing This is one of the most common spelling errors in English. Always test: can you replace it with "who is"? If yes, it's who's. If no, it's whose.

4. Use the 4-step decision process whenever you're unsure Go through the steps: (1) Who owns it? (2) Singular or plural? (3) Apply the apostrophe rule. (4) Person or thing? This systematic approach prevents errors.

5. Pay attention to time expressions in real-world writing News headlines, job descriptions, and official documents frequently use time possessives (today's news, a week's notice, three years' experience). Notice these patterns when you read — they'll become more natural.

Practice All Exercises

All possessive 's exercises include answers and explanations. Available in multiple choice format online, plus downloadable PDF worksheets. Each set builds on the previous one, giving you complete Saxon genitive practice from A1 to B1.

👉 Practice Mixed Possessives →

Total: 80 possessive 's exercises with answers across 4 progressive sets, from beginner (A1) to intermediate (B1) level.

👉 Start with Set 1: Singular Possessives →