A noun can co-occur with an article or an attributive adjective. Verbs and adjectives can't. In the following, an asterisk (*) in front of an example means that this example is ungrammatical.
Nouns are a part of speech typically denoting a person, place, thing, animal or idea. In linguistics, a noun is a member of a large, open lexical category whose members can occur as the main word in the subject of a clause, the object of a verb, or the object of a preposition.
In grammar, a part of speech (also a word class, a lexical class, or a lexical category) is a linguistic category of words (or more precisely lexical items), which is generally defined by the syntactic or morphological behaviour of the lexical item in question. Common linguistic categories include noun and verb, among others. There are open word classes, which constantly acquire new members, and closed word classes, which acquire new members infrequently if at all.
Almost all languages have the lexical categories noun and verb, but beyond these there are significant variations in different languages. For example, Japanese has as many as three classes of adjectives where English has one; Chinese, Korean and Japanese have nominal classifiers whereas European languages do not; many languages do not have a distinction between adjectives and adverbs, adjectives and verbs (see stative verbs) or adjectives and nouns]citation needed[, etc. This variation in the number of categories and their identifying properties entails that analysis be done for each individual language. Nevertheless the labels for each category are assigned on the basis of universal criteria.
Abstract and concrete are classifications that denote whether a term describes an object with a physical referent or one with no physical referents. They are most commonly used in philosophy and semantics. Abstract objects are sometimes called abstracta (sing. abstractum) and concrete objects are sometimes called concreta (sing. concretum). An abstract object is an object which does not exist at any particular time or place, but rather exists as a type of thing, i.e. an idea, or abstraction. The term 'abstract object' is said to have been coined by Willard Van Orman Quine. The study of abstract objects is called abstract object theory.
In traditional philosophy a 'concrete term' is defined as a word which denotes a particular person or thing, and an 'abstract term' is defined as a noun which denotes qualities that exist only as attributes of particular persons or things.
A sentence, accordingly, is said to be concrete if it makes an assertion about a particular subject, and abstract if it makes an assertion about an abstract subject. With reference to literature, however, these terms are often used in an extended way: a passage is called abstract if it represents its subject matter in general or nonsensuous words or with only a thin realization of its experienced qualities; it is called concrete if it represents its subject matter with striking particularity and sensuous detail. In his Ode to Psyche, John Keats uses a concrete description of a local which involveds qualities that are perceived by four senses; hearing, touch, sight and smell.
Initial-stress derivation is a phonological process in English, wherein stress is moved to the first syllable of any of several dozen verbs when they become nouns or adjectives. This is called a suprafix in linguistics. It is gradually becoming more standardized in some English dialects, but is not present in all, and the list of affected words differs from area to area, and whether a word is used metaphorically or not. At least 170 verb-noun (or adjective) pairs exist. Some examples are:
Algeria · Nigeria · Sudan · Ethiopia · Seychelles
Uganda · Zambia · Kenya · South Africa
Afghanistan · Pakistan · India
Nepal · Sri Lanka · Vietnam
China · Hong Kong · Macau · Taiwan
North Korea · South Korea · Japan
Malaysia · Singapore · Philippines · Thailand