car park Iceland shopkeeper website

blackberry grandstand greenhouse small talk

breakwater fall-guy go-kart runway

Many compound nouns are written as one word, but some are written with hyphens or spaces. In modern English, hyphens are less common than they were in the past. A good learner’s dictionary will tell you how each compound is usually written.

Examples of one word

bathroom sheepdog windscreen

Examples of hyphens

check-in fire-fighter son-in-law

Examples of spaces

bottle opener New Year’s Day Prime Minister

We form the plural of most compounds by adding a plural ending to the last part of the compound:

We saw some large greenhouses with vegetables growing in them.

They’re building two new car parks in town.

The compounds mother-in-law, brother-in-law, etc. form their plurals on the first noun:

I’ve got one brother-in-law and two sisters-in-law.

Not: two sister-in-laws

Compound nouns normally have the spoken stress on the first part:

CAR park, BATHroom, WEBsite, BROther-in-law, DOORbell, CHECK-in

However, not all compound nouns follow this rule. Some have spoken stress on the second part, especially in proper names and titles:

Mount EVerest, Prime MINister, New YORK

A good learner’s dictionary will tell you where to put the stress.