Objects & Modifiers

Prepositional Phrases

A preposition plus a noun makes a unit that can do an adjective’s job or an adverb’s. It gets its own two-part shape, and the shape nests inside itself.

What you’ll learn

Draw the diagonal-and-horizontal shape of a prepositional phrase
Work out whether a phrase is adjectival or adverbial
Attach the phrase to the right word
Nest one prepositional phrase inside another

The shape

A preposition — under, from, on, beside, through — takes a noun after it, called its object. Together they form a phrase that modifies something else in the sentence.

The notation is two connected lines: a diagonal dropping from the word being modified, carrying the preposition, and a horizontal carrying its object. Anything modifying the object hangs on a slant below the horizontal, just as it would below the base line.

“The cat slept under the stairs.”

Reed-Kellogg — one connected shape under the verb

detDeterminer
nsubjNominal subject
ROOTRoot of the sentence
prepPrepositional modifier
pobjObject of preposition

Dependency — prep and pobj, with no boundary drawn

Comparing the two views

The connected shape is the point. Reed-Kellogg draws under the stairs as one figure hanging off slept, so its extent is visible — you can see where the phrase begins and ends. The dependency parse gives you prep from slept to under and pobj from under to stairs, which contains the same information but never draws a boundary around it.

Adjectival or adverbial?

The same phrase shape does two different jobs, and which one it is doing depends entirely on what it hangs from.

Hanging from a noun → adjectival. It tells you which one: a parcel from Lisbon.
Hanging from a verb → adverbial. It tells you how, when or where: arrived on Tuesday.

Choosing the wrong anchor is the most common mistake on this topic, and the diagram makes it visible immediately — the phrase is drawn hanging off the wrong word.

Read the phrase and ask what it tells you about
from Lisbon — from Lisbon what? The parcel. So it belongs to the noun.
Test by moving it
An adverbial phrase can usually move to the front of the sentence: On Tuesday a parcel from Lisbon arrived. An adjectival one cannot — From Lisbon a parcel arrived on Tuesday changes what it attaches to.
Hang it from the word it belongs to
Not from the nearest word, and not always from the verb.

“A parcel from Lisbon arrived on Tuesday.”

Reed-Kellogg — one phrase per anchor, visibly different

detDeterminer
nsubjNominal subject
prepPrepositional modifier
pobjObject of preposition
ROOTRoot of the sentence

Dependency — both are prep; only the head distinguishes them

Comparing the two views

Two phrases, two different anchors, and the diagram shows the difference at a glance — one hangs off parcel, the other off arrived. The dependency tree shows it too, but you have to trace the arcs: both prepositions arrive as prep, and only the head each attaches to tells you which is adjectival. Same fact, more work to read.

Phrases inside phrases

The object of a preposition is a noun, and a noun can take a prepositional phrase of its own. So the shape nests: a second diagonal drops from the first phrase’s horizontal, giving the stepped look you see in longer sentences.

There is no limit. at the edge of the field beside the river stacks three deep, each one hanging off the object of the one before.

“We stood at the edge of the field.”

Reed-Kellogg — a second phrase hanging off the first

nsubjNominal subject
ROOTRoot of the sentence
prepPrepositional modifier
detDeterminer
pobjObject of preposition

Dependency — nesting is just another level

Comparing the two views

Nesting is where the dependency tree becomes easier to read than the diagram, which is worth admitting. The tree simply grows another level — of hangs from edge, field from of — and the depth is countable at a glance. The Reed-Kellogg version has to step the shape down and to the right, which gets cramped quickly. Neither notation is uniformly better.

Key terms

Preposition: A word relating a noun to the rest of the sentence. Tagged IN, relation prep. Coarse category ADP. She sat on the chair. We walked through the park after lunch.
See: Determiners & Function Words
Object of the preposition: The noun phrase the preposition governs — the sofa, not just sofa. Drawn on the horizontal, with its modifiers slanting below. In the dependency view the relation pobj sits on the head noun alone; the phrase is that word plus everything hanging from it. She sat on the sofa. A letter from my aunt arrived.
See: Core Arguments
Adjectival phrase: A prepositional phrase modifying a noun. Hangs from that noun. The letter from Melvin arrived. The path along the river floods.
See: Articles, Adjectives & Objects
Adverbial phrase: A prepositional phrase modifying a verb, adjective or adverb. Hangs from that word. She sat on the chair. He runs before breakfast.
See: Adverbs, Adverb Clauses

Practice on a real sentence

Two prepositional phrases, one nested in the other. In the dependency exercise, prep and pobj each occur twice — the button count tells you how many are left.

“She sat on the chair in the corner.”

Parts of speech

Give every word its coarse Universal Dependencies category.

Words 0/8Attempts 0Correct 0Time 0:00

Sentence — select a part of speech below, then click the word(s) it applies to

She sat on the chair in the corner.