A practical english grammar - Vyssaja skola 1978
Noun adjuncts
Sound symbols
A common structure in English consists of two nouns, in which the second noun is the head of the phrase and the first is the modifier. The first noun may show the material of which the second is made, as in brick house or wool suit; it may show the purpose for which it is intended, as in passenger train, school book; or it may express a number of other relationships. There are two important types of noun + noun combinations in English.
Noun-noun compounds. In this structure, the two nouns have joined together so closely that English vocabulary treats them as a single item with a special meaning. They are never separated. The loud stress is always on the first member of the pair, while the second member receives medium (or tertiary) stress. In spelling, compounds are often written as one word, but not always. Here are some examples:
teapot tea party textbook
fountain pen teacup football
coat pocket bookstore birthday party
fire engine typewriter Christmas tree
bus driver lawn mower ashtray
milkman schoolboy tennis racket
There are literally thousands of these compounds in English, and new ones are frequently created. Unfortunately, even the largest dictionaries do not always indicate which combinations of words are compounds and which are not, and so the learner of English can not be sure which part of the combination should be stressed. If the pair is written as one word, it is very likely to be a compound, but the converse of this rule is not true, since a great many compounds are written as two words.
Noun-noun phrases. In these pairings of nouns, the parts are not so closely bound as they are in compounds. Usually the two nouns are stressed equally, or at the end of a phrase, the second normally bears the heavy stress. Either can be stressed for contrastive emphasis, however.
I want a wool suit.
I want a wool suit, not a silk one.
This wool suit is a good one.
Replacement of compounds and phrases by pronouns. As was pointed out earlier, compounds are never separated. This means that neither part of the expression can ever be omitted, or replaced by pronouns. This is not true of noun-noun phrases:
They have two gardens: a vegetable garden and a flower garden.
He has two suits: a wool one and a cotton one.
In the first sentence, it is not possible to replace garden in vegetable garden and flower garden by any kind of pronoun or substitute noun; in the second sentence, suit is readily replaced by one, since wool suit and cotton suit are not compounds but phrases.
What kind of pot is that?
It’s a teapot.
What kind of house do they have?
They have a brick one.
Again, teapot can not be separated; “tea one” is not possible in English. Brick house, however, is a phrase, and the second element can be replaced by one.