You already know the basic rule: the cat's tail, my friend's car. At this level, three areas require extra attention: names ending in -s, hyphenated phrases, and shared vs. individual possession.
Use 's for people and animals; use of for objects, abstract ideas, and parts of things. Organisations and countries can use either.
| Use 's (people & animals) | Use "of" (objects & abstract) | Either possible (organisations/countries) |
|---|---|---|
| the cat's tail my boss's email the horse's saddle the teacher's desk |
the roof of the building the end of the street the result of the match the purpose of the meeting |
the company's success ✓ the success of the company ✓ Poland's capital ✓ the government's decision ✓ |
One noun can describe another. The first noun acts like an adjective, showing type or purpose — not ownership. The first noun is almost always singular, even when the meaning is plural.
In English, 's (or s') is used with time and distance expressions, just as with people. This is a typical B1+ pattern that frequently appears in Cambridge exams.
Rule: singular time word → 's — plural time word → s' (apostrophe after the s, no extra s).
| Singular → 's | Plural → s' | Fixed phrases |
|---|---|---|
| a week's holiday one hour's drive a month's salary today's news |
two weeks' notice three hours' walk six months' rent five years' experience |
a stone's throw away at arm's length for goodness' sake in today's world |
The double possessive combines "of" + possessive noun/'s or possessive pronoun. It is used when talking about one of several things belonging to someone, and creates an important distinction in meaning.
The structure you choose tells the listener whether you mean the container / object type itself, or the contents / quantity inside.
| Noun + Noun → the object/type itself | Noun + of + Noun → the contents/quantity |
|---|---|
| a wine glass = a glass designed for wine (чаша за вино) | a glass of wine = a glass filled with wine (чаша вино) |
| a matchbox = a box for matches (кибритена кутия) | a box of matches = a box containing matches (кутия с кибрит) |
| a milk bottle = a bottle designed for milk | a bottle of milk = a bottle filled with milk |
| a coffee cup = a cup designed for coffee | a cup of coffee = a cup containing coffee |
| a cardboard box = a box made of cardboard | a box of chocolates = a box with chocolates inside |
| Tense | Typical context signals | Active | Passive equivalent |
|---|---|---|---|
| Present Simple | always, every day, generally, facts | They deliver it daily. | It is delivered daily. |
| Present Continuous | right now, at this moment, currently, look! | They are fixing it. | It is being fixed. |
| Past Simple | yesterday, last year, in 1990, specific finished time | They built it in 1990. | It was built in 1990. |
| Past Continuous | when (past), at that moment, while, all night | They were repairing it. | It was being repaired. |
| Present Perfect | just, already, yet, recently, ever/never, since, for (up to now) | They have fixed it. | It has been fixed. |
| Past Perfect | by the time, before (past ref.), already (in past narrative) | They had repaired it. | It had been repaired. |
| Future (will) | tomorrow, next week, soon, I think/believe/expect | They will announce it. | It will be announced. |
| Modals | must, can, should, may followed by base verb | They must complete it. | It must be completed. |