black-board

English compound

A compound is a word composed of more than one free morpheme.

English compounds may be classified in several ways, such as the word classes or the semantic relationship of their components.

Examples by word class
Modifier	Head	Compound
noun	noun	football
adjective	noun	blackboard
verb	noun	breakwater
preposition	noun	underworld
noun	adjective	snowwhite
adjective	adjective	blue-green
verb	adjective	tumbledown
preposition	adjective	over-ripe
noun	verb	browbeat
adjective	verb	highlight
verb	verb	freeze-dry
preposition	verb	undercut
noun	preposition	love-in
adjective	preposition	forthwith
verb	preposition	takeout
preposition	preposition	without

Compound nouns

Most English compound nouns are noun phrases (= nominal phrases) that include a noun modified by adjectives or attributive nouns. Due to the English tendency towards conversion, the two classes are not always easily distinguished. Most English compound nouns that consist of more than two words can be constructed recursively by combining two words at a time. Combining 'science' and 'fiction', and then combining the resulting compound with 'writer', for example, can construct the compound 'science fiction writer'. Some compounds, such as salt and pepper or mother-of-pearl, cannot be constructed in this way, however.

'''Types of compound nouns

Since English is a mostly analytic language, unlike most other Germanic languages, it creates compounds by concatenating words without case markers. As in other Germanic languages, the compounds may be arbitrarily long. However, this is obscured by the fact that the written representation of long compounds always contains blanks. Short compounds may be written in three different ways, which do not correspond to different pronunciations, however:

The ‘solid’ or ‘closed’ forms in which two usually moderately short words appear together as one. Solid compounds most likely consist of short (monosyllabic) units that often have been established in the language for a long time. Examples are housewife, lawsuit, wallpaper, etc.
The hyphenated form in which two or more words are connected by a hyphen. Compounds that contain affixes, such as house-build(er) and single-mind(ed)(ness), as well as adjective-adjective compounds and verb-verb compounds, such as blue-green and freeze-dry, are often hyphenated. Compounds that contain articles, such as mother-of-pearl and salt-and-pepper, are also often hyphenated.
The open or spaced form consisting of newer combinations of usually longer words, such as distance learning, player piano, lawn tennis, etc.

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

In addition to this native English compounding, there is the classical type, which consists of words derived from Latin, as horticulture, and those of Greek origin, such as photography, the components of which are in bound form (connected by connecting vowels, which are most often -i- and -o- in Latin and Greek respectively) and cannot stand alone.

Analyzability (transparency)

In general, the meaning of a compound noun is a specialization of the meaning of its head. The modifier limits the meaning of the head. This is most obvious in descriptive compounds, also known as karmadharaya compounds, in which the modifier is used in an attributive or appositional manner. A blackboard is a particular kind of board, which is (generally) black, for instance.

In determinative compounds, however, the relationship is not attributive. For example, a footstool is not a particular type of stool that is like a foot. Rather, it is a stool for one's foot or feet. (It can be used for sitting on, but that is not its primary purpose.) In a similar manner, the office manager is the manager of an office, an armchair is a chair with arms, and a raincoat is a coat against the rain. These relationships, which are expressed by prepositions in English, would be expressed by grammatical case in other languages. Compounds of this type are also known as tatpurusha compounds.

Both of the above types of compounds are called endocentric compounds because the semantic head is contained within the compound itself -- a blackboard is a type of board, for example, and a footstool is a type of stool.

However, in another common type of compound, the exocentric or bahuvrihi compound, the semantic head is not explicitly expressed. A redhead, for example, is not a kind of head, but is a person with red hair. Similarly, a blockhead is also not a head, but a person with a head that is as hard and unreceptive as a block (i.e. stupid). And, outside of veterinary surgery, a lionheart is not a type of heart, but a person with a heart like a lion (in its bravery, courage, fearlessness, etc.).

Note in general the way to tell the two apart:

Can you paraphrase the meaning of the compound "[X . Y]" to A person/thing that is a Y, or ... that does Y, if Y is a verb (with X having some unspecified connection)? This is an endocentric compound.
Can you paraphrase the meaning if the compound "[X . Y]" to A person/thing that is with Y, with X having some unspecified connection? This is an exocentric compound.

Exocentric compounds occur more often in adjectives than nouns. A V-8 car is a car with a V-8 engine rather than a car that is a V-8, and a twenty-five-dollar car is a car with a worth of $25, not a car that is $25. The compounds shown here are bare, but more commonly, a suffixal morpheme is added, esp. -ed. Hence, a two-legged person is a person with two legs, and this is exocentric.

On the other hand, endocentric adjectives are also frequently formed, using the suffixal morphemes -ing or -er/or. A car-carrier is a clear endocentric determinative compound: it is a thing that is a carrier of cars. The related adjective, car-carrying, is also endocentric: it refers to an object, which is a carrying-thing (or equivalent, which does carry).

These types account for most compound nouns, but there are other, rarer types as well. Coordinative, copulative or dvandva compounds combine elements with a similar meaning, and the compound meaning may be a generalization instead of a specialization. Bosnia-Herzegovina, for example, is the combined area of Bosnia and Herzegovina, but a fighter-bomber is an aircraft that is both a fighter and a bomber. Iterative or amredita compounds repeat a single element, to express repetition or as an emphasis. Day-by-day and go-go-go are examples of this type of compound, which has more than one head.

Analyzability may be further limited by cranberry morphemes and semantic changes. For instance, the word butterfly, commonly thought to be a metathesis for flutter by, which the bugs do, is actually based on an old bubbe-maise that butterflies are petite witches that steal butter from window sills. Cranberry is a part translation from Low German, which is why we cannot recognize the element cran (from the Low German kraan or kroon, "crane"). The ladybird or ladybug was named after the Christian expression "our Lady, the Virgin Mary".

In the case of verb+noun compounds, the noun may be either the subject or the object of the verb. In playboy, for example, the noun is the subject of the verb (the boy plays), whereas it is the object in callgirl (someone calls the girl).

Sound patterns

A black board is any board that is black, and equal prosodic stress can be found on both elements (or, according to psycholinguist Steven Pinker, the second one is accented more heavily.) A blackboard, the compound, may have started out as any other black board, but now is a thing that is constructed in a particular way, of a particular material and serves a particular purpose; the word is clearly accented on the first syllable.

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 phrase. A compound usually has a falling intonation: "bláckboard", the "Whíte House", as opposed to the phrases "bláck bóárd". (Note that this rule does not apply in all contexts. For example, the stress pattern "whíte house" would be expected for the compound, which happens to be a proper name, but it is also found in the emphatic negation "No, not the black house; the white house!"

Compound adjectives

English compound adjectives are constructed in a very similar way to the compound noun. Blackboard jungle, leftover ingredients, gunmetal sheen, and green monkey disease are only a few examples.

A compound adjective is a modifier of a noun. It consists of two or more morphemes of which the left-hand component limits or changes the modification of the right-hand one, as in "the dark-green dress": dark limits the green that modifies dress.

Solid compound adjectives

There are some well-established permanent compound adjectives that have become solid over a longer period, especially in American usage: earsplitting, eyecatching, and downtown.

However, in British usage, these, apart from downtown, are more likely written with a hyphen: ear-splitting, eye-catching.

Other solid compound adjectives are for example:

Numbers that are spelled out and have the suffix -fold added: "fifteenfold", "sixfold".
Points of the compass: northwest, northwester, northwesterly, northwestwards, but not North-West Frontier.

Hyphenated compound adjectives

A compound adjective is hyphenated if the hyphen helps the reader differentiate a compound adjective from two adjacent adjectives that each independently modify the noun. Compare the following examples:

"acetic acid solution": a bitter solution producing vinegar or acetic acid (acetic + acid + solution)
"acetic-acid solution": a solution of acetic acid

The hyphen is unneeded when capitalization or italicization makes grouping clear:

"old English scholar": an old person who is English and a scholar, or an old scholar who studies English
"Old English scholar": a scholar of Old English.
"De facto proceedings" (not "de-facto")

If, however, there is no risk of ambiguities, it may be written without a hyphen: Sunday morning walk.

Hyphenated compound adjectives may have been formed originally by an adjective preceding a noun:

"Round table" → "round-table discussion"
"Blue sky" → "blue-sky law"
"Red light" → "red-light district"
"Four wheels" → "four-wheel drive" (the singular, not the plural, is used)

Others may have originated with a verb preceding an adjective or adverb:

"Feel good" → "feel-good factor"
"Buy now, pay later" → "buy-now pay-later purchase"

Yet others are created with an original verb preceding a preposition.

"Stick on" → "stick-on label"
"Walk on" → "walk-on part"
"Stand by" → "stand-by fare"
"Roll on, roll off" → "roll-on roll-off ferry"

The following compound adjectives are always hyphenated when they are not written as one word:

An adjective preceding a noun to which -d or -ed has been added as a past-participle construction, used before a noun:

"loud-mouthed hooligan"
"middle-aged lady"
"rose-tinted glasses"

A noun, adjective, or adverb preceding a present participle:

"an awe-inspiring personality"
"a long-lasting affair"
"a far-reaching decision"

Numbers spelled out or as numerics:

"seven-year itch"
"five-sided polygon"
"20th-century poem"
"30-piece band"
"tenth-storey window"

A numeric with the affix -fold has a hyphen (15-fold), but when spelled out takes a solid construction (fifteenfold).
Numbers, spelled out or numeric, with added -odd: sixteen-odd, 70-odd.
Compound adjectives with high- or low-: "high-level discussion", "low-price markup".
Colours in compounds:

"a dark-blue sweater"
"a reddish-orange dress".

Fractions as modifiers are hyphenated: "five-eighths inches", but if numerator or denominator are already hyphenated, the fraction itself does not take a hyphen: "a thirty-three thousandth part". (Fractions used as nouns have no hyphens: "I ate only one third of the pie.")
Comparatives and superlatives in compound adjectives also take hyphens:

"the highest-placed competitor"
"a shorter-term loan"

However, a construction with most is not hyphenated:

"the most respected member".

Compounds including two geographical modifiers:

"Afro-Cuban"
"African-American" (sometimes)
"Anglo-Asian"

But not

"Central American".

The following compound adjectives are not normally hyphenated:

Where there is no risk of ambiguity:

"a Sunday morning walk"

Left-hand components of a compound adjective that end in -ly that modify right-hand components that are past participles (ending in -ed):

"a hotly disputed subject"
"a greatly improved scheme"
"a distantly related celebrity"

Compound adjectives that include comparatives and superlatives with more, most, less or least:

"a more recent development"
"the most respected member"
"a less opportune moment"
"the least expected event"

Ordinarily hyphenated compounds with intensive adverbs in front of adjectives:

"very much admired classicist"
"really well accepted proposal"

Compound verbs

modifier	head	examples
preposition	verb	overrate, underline, outrun
adverb	verb	downsize, upgrade
adjective	verb	whitewash, blacklist, foulmouth
noun	verb	browbeat, sidestep, manhandle
preposition	noun	out-Herod, out-fox

A compound verb is usually composed of a preposition and a verb, although other combinations also exist. The term compound verb was first used in publication in Grattan and Gurrey's Our Living Language (1925).

From a morphological point of view, some compound verbs are difficult to analyze because several derivations are plausible. Blacklist, for instance, might be analyzed as an adjective+verb compound, or as an adjective+noun compound that becomes a verb through zero derivation. Most compound verbs originally have the collective meaning of both components, but some of them later gain additional meanings that may predominate the original, accurate sense. Therefore, sometimes the resultant meanings are seemingly barely related to the original contributors.

Compound verbs composed of a noun and verb are comparatively rare, and the noun is generally not the direct object of the verb. In English, compounds such as *bread-bake or *car-drive do not exist. Yet, we find literal action words, such as breastfeed, taperecord and washing instructions on clothing as for example hand wash.

Hyphenation

Compound verbs with single-syllable modifiers are solid, or unhyphenated. Those with longer modifiers may originally be hyphenated, but as they became established, they became solid, e.g.,

overhang (English origin)
counterattack (Latin origin)

There was a tendency in the 18th century to use hyphens excessively, that is, to hyphenate all previously established solid compound verbs. American English, however, has diminished the use of hyphens, while British English is more conservative.

Phrasal verbs

English syntax distinguishes between phrasal verbs and prepositional verbs. Consider the following:

I held up my hand.

I held up a bank.

I held my hand up.

*I held a bank up.

The first three sentences are possible in English; the last one is unlikely. When to hold up means to raise, it is a prepositional verb; the preposition up can be detached from the verb and has its own individual meaning "from lower to a higher position". As a prepositional verb, it has a literal meaning. However, when to hold up means to rob, it is a phrasal verb. A phrasal verb is used in an idiomatic, figurative or even metaphorical context. The preposition is inextricably linked to the verb; the meaning of each word cannot be determined independently but is in fact part of the idiom.

The Oxford English Grammar (ISBN 0-19-861250-8) distinguishes seven types of prepositional or phrasal verbs in English:

intransitive phrasal verbs (e.g. give in)
transitive phrasal verbs (e.g. find out [discover])
monotransitive prepositional verbs (e.g. look after [care for])
doubly transitive prepositional verbs (e.g. blame [something] on [someone])
copular prepositional verbs. (e.g. serve as)
monotransitive phrasal-prepositional verbs (e.g. look up to [respect])
doubly transitive phrasal-prepositional verbs (e.g. put [something] down to [someone] [attribute to])

English has a number of other kinds of compound verb idioms. There are compound verbs with two verbs (e.g. make do). These too can take idiomatic prepositions (e.g. get rid of). There are also idiomatic combinations of verb and adjective (e.g. come true, run amok) and verb and adverb (make sure), verb and fixed noun (e.g. go ape); and these, too, may have fixed idiomatic prepositions (e.g. take place on).

Misuses of the term

"Compound verb" is often used in place of:

"complex verb", a type of complex phrase. But this usage is not accepted in linguistics, because "compound" and "complex" are not synonymous.
"verb phrase" or "verbal phrase". This is a partially, but not entirely, incorrect use. A phrasal verb can be a one-word verb, of which compound verb is a type. However, many phrasal verbs are multi-word.
"phrasal verb". A sub-type of verb phrase, which have a particle as a word before or after the verb.