Most grammar texts define conjunctions as words that “join” or “connect,” and they are usually listed as function words. Content words (nouns, verbs, adjectives and adverbs) generally carry the meaning of a sentence while function words (determiners, conjunctions and prepositions) are the grammatical glue that holds the sentence together. I think these definitions do conjunctions a huge disservice. Instead, I view conjunctions as the Road Signs for Meaning because they demonstrate the relationship between two parts of a sentence, and if students fail to recognize that relationship, comprehension breaks down even though the student understands all of the content words.
Therefore, grammar lessons on conjunctions should start with meaning. Teachers need to ensure that students understand what each conjunction means. I can place conjunctions into five general categories: temporal words (then, after, meanwhile), words that add equal information (and, additionally, also), words that show the opposite or a contrast (but, however, instead), words that demonstrate result (for, therefore, since), and words that state a conditional relationship (if, whether, unless). Conditional conjunctions are difficult for young learners, so you may want to save them for later. Use a chart or word sort to identify conjunctions that fit into each category, focusing on the meanings of the words. [Conjunctions for sorting available at https://literacyleader.com/node/810.]
Next, provide sentences with a conjunction from one category, and show how the meaning stays the same when it is replaced by another conjunction from the same group. Then demonstrate how the meaning of the sentence changes if it is replaced by a conjunction from a different group.
After students have mastered the meanings of the conjunctions, group them by type (coordinating conjunctions, subordinating conjunctions and conjunctive adverbs—depending on the age of your students). Remember coordinating conjunctions with the acronym FANBOYS (for, and, nor, but, or, yet, so). Students should recognize that all of the FANBOYS words are very small words, and little words only need little punctuation. Therefore, when students combine two independent clauses into a compound sentence with a coordinating conjunction, they only need little punctuation: a comma before the conjunction.
Jim went to the basketball game, but Jerry chose to go hiking.
Conjunctive adverbs, on the other hand, are big words, and most of them are even compound words: therefore, nevertheless, meanwhile. Compound words need compound punctuation, so if students join two independent clauses with a conjunctive adverb, they need compound punctuation: a semicolon before the conjunction and a comma after.
Jerry went hiking on Saturday; therefore, he missed the basketball game.
I call subordinating conjunctions dependent clause markers because the only difference between an independent clause and a dependent clause is one word: a subordinating conjunction.
Independent clause: Jerry went hiking on Saturday.
Dependent clause: Since Jerry went hiking on Saturday.
Dependent clause marker: Since
Now the dependent clause needs an independent clause in order to form a complete sentence (complex sentence structure).
Since Jerry went hiking on Saturday, he missed the basketball game.
Jerry missed the basketball game since he went hiking on Saturday.
Notice how the punctuation changes in the two sentences. If the sentence begins with the dependent clause, it is followed by a comma, but if the sentence begins with the independent clause, no comma is used.
In conclusion, conjunctions are important because they identify the relationships between ideas in text, provide variety in our writing, and they tell us how to correctly punctuate that writing. Just remember that if we don’t start with meaning, the rest of the skills will break down.