| This article is part of the grammar course.
You may choose to follow it in a structured way, or read each item separately.
Conjunctions are joining words: they form a join between two units. In its simplest form, a conjuction allows two sentences to be joined to express a connection between them, for example 'We wanted to go to the park but it was raining'. With two separate sentences, 'We wanted to go to the park. It was raining.' no relation is given between the two statements (though of course, one can infer that raining and parks probably don't mix well).
There are two kinds of conjunction:
- Co-ordinating conjunctions, as the name suggests, join two units of equal importance. In English, these are and, but, either, or, neither and nor. They form a closed set.
- Subordinating conjunctions are used to link clauses (or sentences) together in such a way as to show their relationship of meaning. Subordinating conjunctions are such words as although, as, because, if, since, that, though, until, where, when, while, etc. Some of these begin with wh-, and often behave similarly to the other so-called wh- words, the relative pronouns.
The basic structure of a sentence with subordination is:
|He said||that||it was a fine day|
|Main clause||Subordinating conjunction||clause|
Here you can see that the subordinating conjunction ("that") joins the Main Clause, "He said" to another Clause, the Subordinate Clause, "it was a fine day".
One problem is that at times the Main Clause, grammatically speaking, is not the most important idea in a sentence, logically speaking. So it can be difficult to be sure which Clause is the Main Clause. If it has no subordinating conjunction inside it, it is probably the Main Clause.
As with prepositions, there are also compound subordinating conjunctions such as as soon as, so that and so on.
There are words that seem like conjunctions but should not be used as such:
- In formal academic English, use like as a preposition only (with nouns). With verbs (clauses) use the conjunction as. (In informal English, many people use like with verbs (e.g. "like I said"). This is regarded as a mistake in academic writing.
- however and therefore are not technically conjunctions; they are sentence adverbs. You can ignore the jargon: just remember that they are properly used with full stops (or punctuation marks of similar weight, colons and semicolons).