Here, we use the subordinating conjunction “because” to introduce a reason (i.e., being a good spy) for the main clause (i.e., being hated by the bad guys). Subordinating conjunctions have various meanings. Other examples include “although,” “before,” “unless,” and “while.”
Correlative conjunctions are pairs of words that join similar parts of a sentence. The most common of these include:
Either… or… (e.g., We either need a plan or a lot of luck.)
Neither… nor… (e.g., Neither the villain nor his henchmen can stop me!)
Both… and… (e.g., I am outstanding at both spying and drinking martinis.)
Not only… but also… (e.g., I am not only a great spy, but also a keen gardener.)
Note that the terms connected by correlative conjunctions here are of the same type (i.e., noun + noun or verb + verb). This ensures grammatical parallelism (i.e., it keeps different parts of a sentence in balance).
Finally, we have conjunctive adverbs. These aren’t conjunctions, but they link sentences in a similar way. For example, the terms “however” and “therefore” allow us to show how two clauses or sentences are related:
Being a spy is dangerous; however, it’s also great fun.
As a spy, I have many gadgets. I am, therefore, prepared for any situation.
These provide an alternative to standard conjunctions if you need to vary the terms in your work. Just make sure you pick the right one for what you want to express! And, when in doubt, you can always ask a proofreader for help.