Compound noun and adjective

There are four types of compound nouns in English:

• the solid or closed form in which two, usually short, words appear together as one, such as "housewife", "lawsuit", "wallpaper". etc.
• the hyphenated form in which two or more words are connected by a hyphen, such as in "mother-of-pearl", "bridge-builder", etc.
• the open or spaced form consisting of newer combinations of usually longer words, such as "distance learning", "player piano", "lawn tennis", etc.
• the classical form which consists of words derived from Latin, as in "horticulture", and those of Greek origin, as in "photography".

The way compound nouns are combined cannot always be strictly determined, and often a good dictionary may have to be consulted, but certain rules-of-thumb may be of use:

• Solid compounds most likely consist of short (single-syllable) units that often have been established in the language for a long time.
• Hyphenated compounds often have one component, a complex word, that has at least one or two affixes, such as "house-builder", "single-mindedness", etc.
• Open compounds usually consist of components which are not readily combinable in either solid or hyphenated forms, because they would either look strange in such a combination, or are of a recent coinage and have had not sufficient time to be established in any other than open form.

Usage in the U.S. and in the UK differs and often depends on the individual choice of the writer rather than on a hard-and-fast rule, and so, open, hyphenated and closed forms may be encountered for the same compound noun, such as "container ship", "container-ship", or "containership"; "particle board", "particle-board", or "particleboard".

The first component in a compound noun is the modifier[?], because it modifies or limits the meaning of the second component. For example, in the solid compound "footstool", "foot" limits the meaning of "stool" to that of a "stool for one's foot or feet". (It can be used for sitting on but that not its primary purpose). A "foundation stone" is a stone, one of a type and not of any other, with which a "foundation for a building is being laid".

A modifier in a compound fulfils a very similar function to that in an adjective + noun. A "black board" is any board that is black. A "blackboard", the compound, may have started out as any other "black board", but now is constructed in a particular way, of a particular material and serves a particular purpose.

A modifier thus may indicate the purpose the noun stands for, the material of which it is made, or the way it works, is designed or constructed, as in "sand castle", "roundhouse", "workbench" or "particle-board".

One more aspect, that of the sound pattern of compounds that originally started with an adjective modifier , ought to be considered. Sound patterns, such as stresses placed on particular syllables, may indicate whether the word group is a compound or whether it is an adjective + noun. A compound usually has a falling intonation such as "blackboard", the "White House", as opposed to the adjective and noun "black board", or "white house".

Work on Compound adjective is in progress