註釋
English grammar is the body of rules that describe the structure of expressions in the English language. This includes the structure of words, phrases, clauses and sentences.
There are historical, social, cultural and regional variations of English. Divergences from the grammar described here occur in some dialects of English. This article describes a generalized present-day Standard English, the form of speech found in types of public discourse including broadcasting, education, entertainment, government, and news reporting, including both formal and informal speech. There are certain differences in grammar between the standard forms of British English, American English and Australian English, although these are inconspicuous compared with the lexical and pronunciation differences.
Word classes and phrases
Eight types of word ("word classes" or "parts of speech") are distinguished in English: nouns, determiners, pronouns, verbs, adjectives, adverbs, prepositions, and conjunctions. (Determiners, traditionally classified along with adjectives, have not always been regarded as a separate part of speech.) Interjections are another word class, but these are not described here as they do not form part of the clause and sentence structure of the language.
Nouns, verbs, adjectives, and adverbs form open classes - word classes that readily accept new members, such as the noun celebutante (a celebrity who frequents the fashion circles), similar relatively new words. The others are regarded as closed classes. For example, it is rare for a new pronoun to be admitted to the language.
English words are not generally marked for word class. It is not usually possible to tell from the form of a word which class it belongs to except, to some extent, in the case of words with inflectional endings or derivational suffixes. On the other hand, some words belong to more than one word class. For example run can serve as either a verb or a noun (these are regarded as two different lexemes). Lexemes may be inflected to express different grammatical categories. The lexeme run has the forms runs, ran, runny, runner, and running. Words in one class can sometimes be derived from those in another. This has the potential to give rise to new words. The noun aerobics has recently given rise to the adjective aerobicized.
Words combine to form phrases. A phrase typically serves the same function as a word from some particular word class. For example, my very good friend Peter is a phrase that can be used in a sentence as if it were a noun, and is therefore called a noun phrase. Similarly, adjective phrases and adverb phrases function as if they were adjectives or adverbs, but with other types of phrases the terminology has different implications. For example, a verb phrase consists of a verb together with any objects and other dependents; a prepositional phrase consists of a preposition together with its complement (and is therefore usually a type of adverb phrase); and a determiner phrase is a type of noun phrase containing a determiner.
Nouns
Nouns form the largest English word class. There are many common suffixes used to form nouns from other nouns or from other types of words, such as -age (as in shrinkage), -hood (as in sisterhood), and so on, although many nouns are base forms not containing any such suffix (such as cat, grass, France). Nouns are also often created by conversion of verbs or adjectives, as with the words talk and reading (a boring talk, the assigned reading).
Unlike in many related languages, English nouns do not have grammatical gender (although many nouns refer specifically to male or female persons or animals, like mother, father, bull, tigress; see Gender in English). Nouns are sometimes classified semantically (by their meanings) as proper nouns and common nouns (Cyrus, China vs. frog, milk) or as concrete nouns and abstract nouns (book, laptop vs. heat, prejudice). A grammatical distinction is often made between count (countable) nouns such as clock and city, and non-count (uncountable) nouns such as milk and decor. Some nouns can function both as countable and as uncountable such as the word "wine" (This is a good wine, I prefer red wine).
Countable nouns generally have singular and plural forms. In most cases the plural is formed from the singular by adding -[e]s (as in dogs, bushes), although there are also irregular forms (woman/women, foot/feet, etc.), including cases where the two forms are identical (sheep, series). For more details, see English plural.
Certain nouns can take plural verbs even though they are singular in form, as in The government were ... (where the government is considered to refer to the people constituting the government). This, a form of synesis, is more common in British than American English. See English plural: Singulars with collective meaning treated as plural.
English nouns are not marked for case as they are in some languages, but they have possessive forms, formed by the addition of -'s (as in John's, children's), or just an apostrophe (with no change in pronunciation) in the case of -[e]s plurals and sometimes other words ending with -s (the dogs' owners, Jesus' love). More generally, the ending can be applied to noun phrases (as in the man you saw yesterday's sister); see below. The possessive form can be used either as a determiner (John's cat) or as a noun phrase (John's is the one next to Jane's). For details, see English possessive.