Dependency Relations
Modifier Relations
What you’ll learn
- Apply the deletion test that separates a modifier from a core argument
- Tell acl from relcl, and both from advcl
- Recognise a noun phrase doing an adverb's job
- Read a prepositional phrase as two arcs rather than one unit
Delete it and the sentence survives
The engine started reluctantly loses nothing structural when reluctantly goes. Compare a core argument: remove the object from Marta repaired the radio and you are left with a fragment. That test is the whole basis of this family.
The catch is that “optional” is about grammar, not importance. Not is a modifier, and deleting it reverses the meaning of the sentence entirely.
Adverbial modifiers
advmodAdverbial modifier
An adverb modifying something. It is the most polymorphic label in the taxonomy: the same relation attaches an adverb to a verb, to an adjective, or to another adverb, and the arc looks identical in all three.
How spaCy decides: the dependent is an adverb, and the head is whatever it modifies. To read one correctly, follow the arc up and see what it lands on.
“The engine started reluctantly.”
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
- advmodAdverbial modifier
“The soup was unusually salty.”
“She spoke very softly.”
negNegation modifier
Negation. A separate label rather than a kind of advmod, because negation changes truth rather than adding detail.
How spaCy decides: the word is a negator — not, n’t, never. It attaches to whatever it negates, normally the verb.
“The tap does not work.”
- detDeterminer
- nsubjNominal subject
- auxAuxiliary
- negNegation modifier
- ROOTRoot of the sentence
“She never answers her phone.”
npadvmodNoun phrase as adverbial modifier
A noun phrase doing an adverb’s job — measuring duration, distance or time without any preposition to introduce it. Ran three hours, not ran for three hours.
How spaCy decides: a nominal modifying a verb where an adverbial reading is the only sensible one. It is the label that catches adverbial objectives.
“The meeting ran three hours.”
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
- nummodNumeric modifier
- npadvmodNoun phrase as adverbial modifier
“We leave next Tuesday.”
prepPrepositional modifier
A preposition modifying something. The label sits on the preposition itself, and the phrase it introduces is completed by a separate pobj arc beneath it — so a prepositional phrase is always at least two arcs.
How spaCy decides: the word is a preposition, and the head is whatever the phrase modifies. Like advmod, the label is constant while the attachment varies, and the attachment is what changes the meaning.
“The fox slipped through the hedge.”
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
- prepPrepositional modifier
- pobjObject of preposition
“The path beside the canal flooded.”
“She is fond of puzzles.”
Clausal modifiers
Three labels attach an entire clause as a modifier, and they are told apart by what the clause modifies: a verb, or a noun — and if a noun, whether the clause uses a relative pronoun.
advclAdverbial clause modifier
An adverbial clause: a whole clause modifying a verb, saying when, why, or under what condition. The label goes on the inner clause’s verb.
How spaCy decides: a subordinate clause attached to a verb rather than to a noun, normally introduced by a subordinating conjunction carrying mark.
“We waited until the rain stopped.”
- nsubjNominal subject
- ROOTRoot of the sentence
- markMarker
- detDeterminer
- advclAdverbial clause modifier
“If the alarm sounds, leave quickly.”
relclRelative clause modifier
A relative clause modifying a noun, introduced by a relative pronoun — who, which, that — or by nothing at all.
How spaCy decides: a clause attached to a noun where the noun also plays a role inside that clause. The label goes on the clause’s verb and points at the noun.
“The baker who trained me retired.”
- detDeterminer
- nsubjNominal subject
- relclRelative clause modifier
- dobjDirect object
- ROOTRoot of the sentence
“The song she wrote won awards.”
aclClausal modifier of noun
The other clause-on-a-noun relation, for clauses that are not relative clauses — participles and infinitives modifying a noun.
How spaCy decides: a clause attached to a noun with no relative pronoun and no gap for one. The man wearing a hat has no missing who; the man who wore a hat does.
“The man wearing a hat waved.”
- detDeterminer
- nsubjNominal subject
- aclClausal modifier of noun
- dobjDirect object
- ROOTRoot of the sentence
“Her decision to resign surprised us.”
Key terms
- Modifier
- Optional detail. Deleting it leaves a grammatical sentence, which is the test that separates this family from the core arguments. The tired birds slept. Birds sing at dawn.
See: Grammar Basics
- Adverbial clause
- A clause modifying a verb, labelled
advclon its own verb and normally introduced by amark. We left because it rained. When the bell rang, everyone stood.See: Adverb Clauses
- Relative clause
- A clause modifying a noun, where the noun also has a role inside the clause. Labelled
relcl; the relative pronoun may be absent. The violin that she inherited needs strings. The letter you sent arrived. — no pronoun at all.See: Adjective Clauses
- Adverbial objective
- A noun phrase used adverbially, labelled
npadvmod. Looks like an object and behaves like an adverb. We waited an hour. She walked home.
Practice on a real sentence
prep and pobj each occur twice and the buttons stay live after your first correct answer. The second phrase modifies a noun rather than the verb — check where each arc lands.“She sat on the chair in the corner.”
Word dependencies
Pick a relation, click the head, then click the dependent.
Sentence — select a relation below, then click the words it connects
She sat on the chair in the corner.
Dependency tree — word-order columns
The dependency tree is built here as each relation is confirmed