Simply put, conjunctions are words that join. Conjunctions may join two nouns or pronouns together, or they may join entire phrases, clauses, or sentences together. The four kinds of conjunctions are coordinating conjunctions, correlative conjunctions, subordinating conjunctions, and conjunctive adverbs.
The coordinating conjunctions are and, but, for, or, nor, so, and yet. Coordinating conjunctions are placed between the words or phrases they join.
Tom and Rose got married last week.
Steve likes running, but his brother likes hiking.
We can order pizza or chicken.
Correlative conjunctions are sets of connecting words that work together to show a relationship between parts of a sentence. The two parts of a correlative conjunction are separated from one another within the sentence.
Alice enjoys both skiing and hunting.
Sam not only takes martial arts but also studies philosophy.
Subordinating conjunctions are used to create a complex sentence by joining a subordinate clause to an independent clause
You should rest until you feel better.
Since it was too cold, we stayed inside and watched a movie.
Technically, conjunctive adverbs are adverbs, not conjunctions. As such, they may not always be included on other lists of conjunctions you may see. Although they are adverbs, conjunctive adverbs still join clauses together smoothly by relating information and ideas. They may join two separate sentences or join independent clauses within one sentence.
Albert does not like seafood; however, he is usually willing to try other types of food.
It was raining on Friday. Therefore, we had to cancel the school picnic.