Conjunctions are also known as linking words (or linkers), and for a very good reason: they connect ideas. In the most basic of sense and broadly-speaking, conjunctions can be split into several categories, but will not be mutually exclusive to only one category.
Conjunctions of idea
As they sound, conjunctions of idea link ideas. They can be categorized generally as follows:
|To add an idea||To show contrast||To give the reason||To give the result|
|Typically ‘and’||Typically ‘but’||Typically ‘because’||Typically ‘so’|
|Also, as well, too, in addition, furthermore, moreover||However, despite, in spite of, on the other hand, although, even though, though, in contrast, while, whereas||As, due to, for this reason, since||Therefore, as a result, so that, in order to|
Conjunctions of time
Once again as their name suggests, these conjunctions reveal the time relationship between actions. Typical examples include before, after, then, while, since, as soon as, until etc.
Note how some conjunctions can represent idea or time (while and since are the obvious examples), but the context will usually reveal which.
I came here since I don’t like the other restaurant. (idea)
I have been here since 2pm. (time)
These conjunctions consist of pairs that must not be adapted. Examples:
I will have either the pizza or the pasta.
I like neither milk nor cheese.
Many of the conjunctions listed above are coordinating conjunctions, meaning that they link words or clauses with the same value. Examples:
I ate soup and a sandwich.
I went to see that movie but I didn’t like it.
In these types of conjunctions, the linking word stays in the middle.
Likewise, many of the conjunctions above, along with others including all of the conjunctions that can be used in conditional sentences (if, whether, unless, as long, in case), are subordinating conjunctions, meaning that one action or clause is dependent on the other.
I’ll go to the party if you go.
Richard was fitter than many of his colleagues despite being older.
In these cases, the conjunction can also be used at the beginning, as long as the clauses are inverted and a comma is used.
If you go, I’ll go.
Despite being older, Richard was fitter than many of his colleagues.