Conjunctions are used to connect a variety of sentence elements. They can connect smaller parts of writing, such as words and phrases, but they are also used to connect separate sentences, or independent clauses, together into bigger and more complex sentences. More on sentence types.
There are three main types of conjunctions: coordinating conjunctions, subordinating conjunctions, and conjunctive adverbs.
Coordinating conjunctions are often referred to with the acronym FANBOYS: for, and, nor, but, or, yet, so. Coordinating conjunctions connect different words, phrases, or clauses by allowing each to function together while still maintaining their potential independence.
Hint: When a coordinating conjunction is used to connect two independent clauses (or sentences) together, a comma should be placed in front of the coordinating conjunction. This creates a compound sentence.
Example: I was up late last night, so I am tired today.
Subordinating conjunctions come at the beginning of subordinate clauses and are used to connect the subordinate clause to the rest of the sentence (also referred to as the independent clause). Common subordinating conjunctions include after, as, although, because, before, even though, if, once, rather than, since, that, though, unless, until, when, whenever, whereas, while.
Subordinating conjunctions can be moved around or, at the very least, the clauses they are attached to can be. If a subordinating conjunction comes at the beginning of a sentence, a comma is needed where the subordinate clause ends. If it comes in the middle of a sentence, no comma is necessary.
Example: Because I was up late last night, I am tired today.
Or: I am tired today because I was up late last night.
Notice how the above example can be organized either way and it still makes sense? Subordinating conjunctions have this ability. The key is to punctuate either one appropriately.
Conjunctive adverbs are transitional words used to connect one sentence to another. Common conjunctive adverbs include additionally, in addition, moreover, also, consequently, furthermore, otherwise, instead, for instance, for example, however, on the other hand, conversely, nevertheless, accordingly, therefore, generally, in fact, in other words, in conclusion, finally. Unlike subordinating conjunctions, conjunctive adverbs cannot be moved around because they show how the 2nd clause, or sentence, is connected to the first.
When a conjunctive adverb is used between two sentences, generally a semicolon should be placed in front of the conjunctive adverb and a comma should be placed after it.
Example: I was up late last night; consequently, I am tired today.
Correlative conjunctions are a combination of a coordinating conjunction and another word (example: In the sentence both John and I are having a hard time with the homework, both…and are the correlative conjunctions.)
The use of conjunctions makes writing more interesting by giving it variety, so writers should use a variety of conjunctions to make this happen. The key, of course, is to use a variety of conjunctions and to punctuate them appropriately.