Conjunction - a part of speech that connects pieces of a sentence.
Conjunctions allow us to make meaningful connections between ideas in our writing; however, we need to make sure we use the correct type of conjunction, and the correct punctuation.
A coordinating conjunction links two parts of a sentence that carry similar grammatical weight. The relationship between these two parts is clear and direct.
Common coordinating conjunctions are for, and, nor, but, or, yet and so.
Examples
Tom and Jerry fought one another.
I like sushi but not sashimi.
If both parts are independent clauses, a comma should be introduced before the coordinating conjunction.
Examples
The sky was getting darker, so she decided to go home.
The food tasted awful, yet I had to finish it.
Correlative conjunctions act in a similar way to coordinating conjunctions, but they come in pairs.
Common correlative conjunctions are both ... and, either ... or, just as ... so, neither ... nor, not only ... but also, and whether ... or.
Examples
Both Mario and Luigi speak Japanese.
Not only do I jog every morning, I also play sport on the weekend.
Subordinating conjunctions link dependent and independent clauses in a specific way.
There are many subordinating conjunctions: some common ones are after, although, as, because, even though, if, so that, though, unless, and until.
If a subordinating conjunction is placed in the middle of a sentence it is usually not preceded by a comma. (This is the opposite of what is done with coordinating conjunctions.)
Example
I went to the shop to buy some food because I was hungry.
However, if a subordinating conjunction is placed at the beginning of a sentence, the opening clause is followed by a comma.
Example
Even though they were scared, they resisted the order.
Conjunctive adverbs are adverbs that perform the role of a conjunction.
A conjunctive adverb links independent clauses in the same way as a coordinating conjunction; however, it represents a stronger division of the sentence parts and is therefore accompanied by a semicolon.
Some common conjunctive adverbs are finally, furthermore, however, indeed, nevertheless, still, therefore and thus.
Examples
Dressing sharply is always a good idea; indeed, it is essential in some professions.
Conjunctions can be difficult to use; therefore, we should study them carefully.