Prepositions, conjunctions, and interjections are relaters, joiners, and attention-getters in sentences. They connect ideas for readers.
Alas, we've poured so much filth into our water that much of it is undrinkable, and no life can live in it.
—from "To the Residents of A.D. 2029" written by Bryan Woolley
In the sentence, prepositions (in blue), a conjunction (in red), and an interjection (in green) provide key connections.
A preposition is a word that relates a noun or pronoun that appears with it to another word in the sentence. Most prepositions are one word (in, with, for), but some are made up of two or three words (in addition to, instead of).
A prepositional phrase is a group of words that includes a preposition and a noun or pronoun used as the object of the preposition.
In the following two examples, the preposition is in blue and the object is in italics:
outside the gate
within a short distance
Many words can be either prepositions or adverbs, depending upon how they are used. Prepositions have objects; adverbs do not.
Preposition – Perry sits behind me.
Adverb – The dog followed behind.
A conjunction is a word used to connect other words or groups of words. Coordinating conjunctions and correlative conjunctions join similar kinds of words. Subordinating conjunctions connect two ideas by making one of them less important than the other.
Coordinating – Allen put lettuce and tomato on his sandwich.
Correlative – Both Janice and her mother attended the lecture.
Subordinating – They sat in the back since they arrived late.
A conjunctive adverb is an adverb that acts as a conjunction to connect complete ideas. It often acts as a transition, or bridge, between different ideas.
Janice and her mother arrived late; therefore, they had to sit in the back of the auditorium.
An interjection is a word or phrase that expresses feeling or emotion and functions independently of the rest of the sentence. Some common interjections are aha, alas, goodness gracious, hurray, oh my, well, whew, and wow.