Definition: A conjunction is a word that joins words, phrases, or clauses. There are several types of conjunctions and several other types of words that act as conjunctions.
Joining words: You should wait before grabbing one of those tempting but hot cookies.
Joining phrases: We have to drive across two states and around a lake to get to Grandmother’s house.
Joining clauses: Because you didn’t do your homework, you will need to miss recess.
Definition: A coordinating conjunction connects words, phrases, or clauses that are grammatically equal. In other words, the conjunction can join several nouns or several phrases or several clauses. The coordinating conjunctions are and, but, or, nor, for, so, and yet.
Joining nouns: We can have pizza, spaghetti, or lasagna for dinner.
Joining verbs: The puppies in the dog park chased, wrestled, and swam all afternoon.
Joining adjectives: The forest behind your house seems dark and mysterious.
Joining phrases: We left on time but arrived late because of the storm.
Joining clauses: The dragon refused to eat people for he found them rather foul tasting.
Each coordinating conjunction connects ideas in a slightly different way.
And – combines two or more positive ideas.
But – connects two or more true but contrasting ideas.
Or – presents a choice between ideas. Only one of the choices is true or possible.
Nor – combines two or more negative ideas. Neither of the ideas is true or possible.
Yet – connects two or more ideas that are somewhat contrasting.
For – explains a reason or purpose.
So – shows an effect or result.
Beware – so can also be so that, which is a subordinating conjunction. Sometimes we say so when we mean so that.
We are going to the movies, so we can’t watch that program.
You need to be here on time so we can get to the movie before it starts.
You need to be here on time so that we can get to the movies before it starts.
Punctuating Coordinate Conjunctions
Coordinating conjunctions have a comma before them when they join two independent clauses. (A simple sentence is an independent clause.) Both clauses must make sense by themselves.
I know I brought my pencil. I can’t find it.
I know I brought my pencil, but I can’t find it.
Often a conjunction is used at the end of a series. That conjunction is usually preceded by a comma in American English. British English writers often leave out that “terminal comma” or “serial comma.” The conjunction can be repeated for an emphatic effect instead of using commas.
I have English, math, and science homework.
I have English and math and science homework.
Note: Can you start a sentence with a coordinating conjunction? Most teachers say no, but I’m sure you’ve noticed sentences beginning with and or but in books that you have read. It can be done for effect if it is done on purpose. Many professional writers often ignore the “rules.” That is because they know the rules and can choose to break them when they want a certain effect. Most teachers require students to demonstrate that they know the rules before allowing them to break them.