COMPOUND NOUNS

Formation

Words can be combined to form compound nouns. These are very common, and new combinations are invented almost daily. They normally have two parts. The second part identifies the object or person in question (man, friend, tank, table, room). The first part tells us what kind of object or person it is, or what its purpose is (police, boy, water, dining, bed):

What type / what purpose	What or who
police	man
boy	friend
water	tank
dining	table
bed	room

The two parts may be written in a number of ways :
1. as one word.
Example: policeman, boyfriend
2. as two words joined with a hyphen.
Example: dining-table
3. as two separate words.
Example: fish tank.
There are no clear rules about this - so write the common compounds that you know well as one word, and the others as two words.

The two parts may be:	Examples:
noun + noun	bedroom water tank motorcycle printer cartridge
noun + verb	rainfall haircut train-spotting
noun + adverb	hanger-on passer-by
verb + noun	washing machine driving licence swimming pool
verb + adverb*	lookout take-off drawback
adjective + noun	greenhouse software redhead
adjective + verb	dry-cleaning public speaking
adverb + noun	onlooker bystander
adverb + verb*	output overthrow upturn input

Compound nouns often have a meaning that is different from the two separate words.
Stress is important in pronunciation, as it distinguishes between a compound noun (e.g. greenhouse) and an adjective with a noun (e.g. green house).
In compound nouns, the stress usually falls on the first syllable:

a 'greenhouse = place where we grow plants (compound noun)
a green 'house = house painted green (adjective and noun)
a 'bluebird = type of bird (compound noun)
a blue 'bird = any bird with blue feathers (adjective and noun)

* Many common compound nouns are formed from phrasal verbs (verb + adverb or adverb + verb).

Examples

breakdown, outbreak, outcome, cutback, drive-in, drop-out, feedback, flyover, hold-up, hangover, outlay, outlet, inlet, makeup, output, set-back, stand-in, takeaway, walkover.