4.3 Prepositions and Prepositional Phrases

Types of Prepositions

Prepositions connect words and ideas in a sentence, showing relationships like time, place, and direction. They're small words that do a lot of heavy lifting. Without them, you'd have no way to say where something is, when it happened, or how it got there.

A prepositional phrase starts with a preposition and ends with its object (a noun or pronoun), plus any modifiers in between. These phrases can work as adjectives or adverbs, adding detail and precision to your writing.

Simple and Compound Prepositions

Simple prepositions are single words that express basic relationships:

• in, on, at, for, with, by, to, from, about, between

Compound prepositions are made up of two or more words that function as a single preposition. They tend to express more specific or nuanced relationships:

• in front of, according to, on behalf of, because of, in addition to, out of

Both types work the same way grammatically. They introduce prepositional phrases and connect nouns or pronouns to other parts of the sentence. The difference is just complexity: "in the room" uses a simple preposition, while "in front of the room" uses a compound one.

Prepositions of Time, Place, and Direction

Prepositions fall into three major categories based on the kind of relationship they describe.

Time prepositions indicate when something happens:

• At for specific times: at noon, at 3:00 PM
• In for longer periods: in July, in the morning, in 2024
• On for days and dates: on Monday, on December 5th
• During/throughout for durations: during the lecture, throughout the semester

Place prepositions show where something is located:

• In for enclosed spaces: in the box, in the classroom
• On for surfaces: on the table, on the wall
• Under/above/between for relative position: under the bed, above the door, between the shelves

Direction prepositions express movement from one point to another:

• To for destinations: to the store
• Through for passing within: through the tunnel
• Toward/away from for orientation: toward the city, away from the noise

The key distinction: place prepositions describe a fixed position, while direction prepositions imply motion.

Prepositional Phrases

Structure and Function of Prepositional Phrases

Every prepositional phrase has the same basic structure:

The object of the preposition is always a noun or pronoun. Any adjectives or articles between the preposition and its object are part of the phrase too.

• in the garden → preposition: "in," object: "garden," modifier: "the"
• under the bright blue sky → preposition: "under," object: "sky," modifiers: "the bright blue"

You can stack multiple prepositional phrases in a single sentence to build layers of detail: The cat on the mat in the corner slept through the afternoon. That sentence has three prepositional phrases, each adding more specific information.

Adjectival and Adverbial Prepositional Phrases

Prepositional phrases do one of two jobs in a sentence: they modify nouns (acting as adjectives) or they modify verbs, adjectives, or adverbs (acting as adverbs).

Adjectival prepositional phrases modify a noun or pronoun. They answer questions like which one? or what kind?

• The book on the shelf is mine. → "On the shelf" tells you which book.
• The woman in the red coat waved. → "In the red coat" tells you which woman.

These phrases almost always appear right after the noun they modify.

Adverbial prepositional phrases modify a verb, adjective, or adverb. They answer questions like how?, when?, where?, or why?

• She spoke with confidence. → "With confidence" tells you how she spoke.
• He arrived before dawn. → "Before dawn" tells you when he arrived.
• They practiced in the gymnasium. → "In the gymnasium" tells you where they practiced.

Here's the tricky part: the same phrase can be adjectival or adverbial depending on what it modifies. Compare these two sentences:

• The meeting in the morning was canceled. → Adjectival, modifying "meeting" (which meeting?)
• We'll leave in the morning. → Adverbial, modifying "leave" (when will we leave?)

To figure out which type you're dealing with, ask yourself: Is this phrase describing a noun, or is it telling me something about the action? That question will point you to the right answer every time.