Dependency Relations
Function Word Relations
det and aux together account for well over a fifth of every arc in the app’s corpus.What you’ll learn
- Attach determiners and auxiliaries to the right head
- Tell a particle from a preposition that looks identical
- Recognise the dummy there and why it takes its own label
- Know why this model has no copula relation, and what it uses instead
Little meaning, heavy lifting
You cannot paraphrase the. It contributes no content you could point at, but removing it from the librarian found a manuscript changes the sentence from English into something a parser struggles with. That is what a function word is.
For reading a tree they are the easy ones — these arcs are short, predictable and land where you expect. Two are worth care: prt, which is easy to mistake for a preposition, and mark, which is easy to mistake for a conjunction.
Determiners
detDeterminer
An article or demonstrative attaching to its noun. The single most common relation after the subject, and the most mechanical.
How spaCy decides: the word is a determiner, and its head is the noun it introduces. It attaches to the noun itself, never to an adjective sitting between them.
“The librarian found a manuscript.”
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
- dobjDirect object
“Those lanterns need new wicks.”
predetPredeterminer
A word sitting in front of a determiner — all the windows, such a racket. It attaches to the noun, alongside the determiner rather than above it.
How spaCy decides: a quantifier or such preceding a determiner in the same noun phrase. Without a determiner following, the same word is usually a plain det instead.
“All the windows rattled.”
- predetPredeterminer
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
“Such a racket woke everyone.”
Auxiliaries
auxAuxiliary
A helping verb attaching to the main verb. Crucially the main verb is the head and the auxiliary is the dependent — so in has finished, the root is finished, not has.
How spaCy decides: the word is an auxiliary or modal, and the lexical verb it supports is its head. Infinitival to is also an aux, which surprises most readers.
“She has finished the report.”
- nsubjNominal subject
- auxAuxiliary
- ROOTRoot of the sentence
- detDeterminer
- dobjDirect object
“They will arrive tomorrow.”
“He can swim well.”
auxpassPassive auxiliary
The auxiliary specifically forming a passive. It travels with nsubjpass; seeing one without the other usually means the parse is wrong.
How spaCy decides: a form of be (or get) supporting a past participle whose subject is the affected thing. When a passive also has a perfect auxiliary, only the passive-forming one gets this label.
“The fence was repaired.”
- detDeterminer
- nsubjpassPassive nominal subject
- auxpassPassive auxiliary
- ROOTRoot of the sentence
“Our flight has been delayed.”
Markers, particles and clitics
markMarker
A subordinating word introducing a clause — because, until, whether, that. It attaches to the verb of the clause it introduces, not to the verb of the clause outside.
How spaCy decides: the word introduces a subordinate clause. That is what separates it from cc, which joins two things of equal rank.
“He left before the storm arrived.”
- nsubjNominal subject
- ROOTRoot of the sentence
- markMarker
- detDeterminer
- advclAdverbial clause modifier
“She hopes that nobody minds.”
prtParticle
A verb particle — the off of turn off. It belongs to the verb and changes its meaning; it is not introducing a phrase.
How spaCy decides: the word looks like a preposition but has no object of its own. That is the whole test, and it is why the particle can move: both turned off the lamp and turned the lamp off are the same relation.
“She turned off the lamp.”
- nsubjNominal subject
- ROOTRoot of the sentence
- prtParticle
- detDeterminer
- dobjDirect object
“He gave the plan up.”
caseCase marking
Case marking — in English, essentially just the possessive ’s, which the tokenizer splits off as a word in its own right.
How spaCy decides: the clitic attaches to the possessor, and the possessor attaches to the thing owned. So a possessive is always two arcs.
“The teacher's notes vanished.”
- detDeterminer
- possPossession modifier
- caseCase marking
- nsubjNominal subject
- ROOTRoot of the sentence
“The mayor's letter arrived.”
- detDeterminer
- possPossession modifier
- caseCase marking
- nsubjNominal subject
- ROOTRoot of the sentence
explExpletive
The dummy there of there is, there remains. It occupies the subject position without naming anything.
How spaCy decides: there in subject position with no locative meaning. The locative there of put it there is an ordinary advmod.
“There stood a lighthouse nearby.”
- explExpletive
- ROOTRoot of the sentence
- detDeterminer
- dobjDirect object
- advmodAdverbial modifier
“There were no seats left.”
- explExpletive
- ROOTRoot of the sentence
- detDeterminer
- attrAttribute
- aclClausal modifier of noun
The one you will never see
copCopulaNot produced by this model
A copula relation exists in the taxonomy, and this model never produces it. It appears nowhere in the app’s corpus and could not be elicited by any test sentence.
The reason is a genuine disagreement between annotation schemes. Universal Dependencies treats the complement as the head of a copular sentence and hangs be beneath it as a cop. The English pipeline here does the opposite: be is the root, and the complement hangs off it as an attr or an acomp.
“She is a doctor.”
- nsubjNominal subject
- ROOTRoot of the sentence
- detDeterminer
- attrAttribute
“The soup is cold.”
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
- acompAdjectival complement
Key terms
- Function word
- A word carrying grammatical rather than lexical meaning. Determiners, auxiliaries, markers and particles. The kettle had whistled. — a determiner and an auxiliary. We left because it rained. — a marker.
- Auxiliary
- A helping verb. It is the dependent, not the head — the lexical verb is the root. She has finished. The road was flooded.
See: Modal Auxiliaries
- Particle
- Part of a phrasal verb, labelled
prt. Distinguished from a preposition by having no object of its own. The plane took off. She looked the word up. - Expletive
- A placeholder filling a grammatical slot without naming anything. In English, the dummy there. There is a bird in the yard. There were no seats left.
Practice on a real sentence
aux and a mark, and the mark attaches downward into the clause it introduces rather than up to the verb before it.“She wondered whether he was sorry he had hurt her.”
Word dependencies
Pick a relation, click the head, then click the dependent.
Sentence — select a relation below, then click the words it connects
She wondered whether he was sorry he had hurt her.
Dependency tree — word-order columns
The dependency tree is built here as each relation is confirmed