In linguistics and the study of grammar, a conjunction is an item that connects units such as words, phrases, or clauses. An example is and in English salt and pepper, but conjunctions can comprise multiple words, and need not even be adjacent: neither... nor for instance. Typically, co-ordinating and subordinating conjunctions are distinguished in English, with the former linking items that are seen as semantically equal (such as and; or), while the latter refers to those of a different grammatical status (for example, because and unless). Modern grammarians often refer to co-ordinators and subordinators instead of co-ordinating and subordinating conjunctions; the latter are more numerous and have a wider range of uses.[1]
The units which are joined by a conjunction could be nouns, adjectives or clauses:
Conjunctions also operate as paired words (correlatives):
The following are examples of simple, complex and correlative subordinators:
Although units such as nouns or phrases linked by a conjunction are often equivalent in English and so can appear in either order (I ride a bike and I drive a car; or I drive a car and I ride a bike), and can also be used to express a result, so the order here is fixed, e.g. Mary stood up and left. The latter case may be taken as Mary stood up and then left, i.e. the complex subordinator and then with partial ellipsis (item deletion).
Confusion between conjunctions and relative pronouns may arise because that can be a subordinating conjunction (Mary thinks that Bill is wrong), or a relative pronoun (as in Mary found the book that Bill needed). English wh- words (including that!) introduce a relative clause and refer to an antecedent that they replace. The test is to see if there is a relationship between the clauses, e.g. Mary found the book, and Bill needed the same book, so who is a relative pronoun in Mary found the book that Bill needed. No such relationship exists in Mary thinks that Bill is wrong.
Co-ordinating conjunctions join together items which can be taken as semantically equal or equivalent, but when looking at word arrangement alone, syntactically this is not the case. Consider the following examples:
Although either item can be replaced by who, only the first one can be moved to the head of the sentence. This suggests that the two items occupy different positions in a syntactic structure, with the second one subordinate. Syntacticians model this restriction by allowing a conjunction to form the 'head' of a conjunction phrase (ConjP), with the second element more deeply embedded inside it, meaning that it cannot be moved:
In this structure, the head and Fred form an incomplete structure and Fred that is not a phrase, represented as Conj'.[3] Items outside this may be moved, but those within may not be, showing that syntax and semantcs do not necessarily align. This X-bar theory is standard in modern syntactic study and also applies to every other type of phrase and sentence.
Other languages also employ conjunctions: in Japanese, for instance, と to and や ya are co-ordinating conjunctions, with to linking a full set of items while ya is used for an open-ended list:
A conjunct is a type of adverbial, i.e. an element which introduces extra information about how, when or how often events took place; conjunct adverbials specifically link otherwise-independent clauses, sentences, or (in writing) paragraphs. These can be used to list, summarise or contrast information, among other uses (Firstly; to conclude; however). Conjunctions, by contrast, are words that are an essential part of the sentence itself and mark a relationship of co-ordination or subordination that expresses a complete idea.