There are only seven coordinating conjunctions in the English language, and they are easily remembered by the acronym FANBOYS:
Coordinating conjunctions signify the relationship between two independent clauses (IC), allowing the writer to specify meaning. In other words, when we construct a compound sentence using a coordinating conjunction, we ask our readers to understand that the two ideas logically relate to each other in the way in which we specify:
In addition to signifying a specific relationship between ideas, the compound structure also tells the reader that the ideas in these clauses are valued equally: one idea is no more important than the other. I may choose to indicate contrast between ideas by using the coordinating conjunction "but," wanting my reader to see the difference(s) between my ideas, yet I am also indicating to my reader that each independent clause should be equally valued.
A compound sentence contains two separate subject and verb pairs. You can combine two simple sentences together with a comma and a coordinating conjunction to make one compound sentence. Here are some examples:
F – for I drank some water, for I was thirsty.
She put on a sweater, for it was cold outside.
*for means the exact same thing as because. The only difference is that when you use for to join two sentences together into one compound sentence, you need to use a comma before it. When you use because to join to sentences, you don’t use a comma before it.
A – and He was tired, and he had a headache.
N – nor She doesn’t drink milk, nor does she eat butter.
I can’t whistle, nor can I sing.
He didn’t study last night, nor did he read his book.
They were not wearing jackets, nor were they carrying umbrellas.
*nor means “also not”. Nor requires unusual grammar. The first sentence will contain a negative verb. The second sentence will contain what looks like an interrogative affirmative verb form. An auxiliary verb (do/does/did, is/am/are/was/were), modal verb (can/could/will/would/may/might/must/should), or be main verb (is/am/are/was/were) comes after nor and before the subject, and then the main verb comes after the subject.
B – but Tom studied a lot, but he didn’t pass the test.
O – or He can buy the book, or he can borrow it from the library.
Y – yet Tom studied a lot, yet he didn’t pass the test.
*yet means the same thing as but.
S – so Maria was thirsty, so she drank some water.
It was cold outside, so she put on a sweater.