Verbals

Infinitives

to plus a verb makes a form that is not a verb any more — it can be a subject, an object, a modifier. The first of three non-finite forms, and the one with the clearest signal.

What you’ll learn

Recognise an infinitive and tell it from a prepositional phrase
Work out what job an infinitive is doing in its sentence
Draw an infinitive on a pedestal when it fills a noun slot
Keep an infinitive's own object attached to it

The marker and the trap

An infinitive is to plus the base form of a verb: to visit, to forgive, to run. It carries no tense, so it can never be the main verb of a clause.

The trap is that to is also a very common preposition. The test is what follows it: a verb makes an infinitive, a noun makes a prepositional phrase.

She hopes to visit Lisbon. — verb after to. Infinitive.
She travelled to Lisbon. — noun after to. Preposition. See Prepositional Phrases.

Infinitive after a verb

The commonest position: after a verb like hope, want, try, need, decide. The infinitive completes the main verb’s meaning, so it hangs beneath it on the preposition-like diagonal-and-horizontal shape, with to on the diagonal.

“She hopes to visit Lisbon.”

Reed-Kellogg — the infinitive hangs beneath the main verb

nsubjNominal subject
ROOTRoot of the sentence
auxAuxiliary
xcompOpen clausal complement
dobjDirect object

Dependency — xcomp, with its own object

Comparing the two views

The tree treats the infinitive as a small clause of its own: visit becomes an xcomp — an “open clausal complement” — with Lisbon as its direct object rather than hopes’. That is exactly right and easy to miss in the Reed-Kellogg version, where the two verbs sit in visually similar places. If you ever wonder which verb owns an object, the tree answers it immediately.

Infinitive as the subject

An infinitive can fill a noun slot outright. To forgive takes courage. — the thing that takes courage is to forgive, so the whole infinitive is the subject.

The notation for “a whole construction filling one slot” is a pedestal: the infinitive is drawn on a raised stand sitting in the subject position. The stand is what says “treat all of this as one noun”.

Find the main verb
takes. Everything else has to fit around it.
Ask what does it
“What takes courage?” → to forgive, all of it.
Put it on a pedestal in the subject slot
The stand lifts the construction into the slot without pretending it is a single word.

“To forgive takes courage.”

Reed-Kellogg — the infinitive raised on a pedestal

auxAuxiliary
csubjClausal subject
ROOTRoot of the sentence
dobjDirect object

Dependency — csubj, no elevation needed

Comparing the two views

Reed-Kellogg has a dedicated device — the pedestal — for “a construction occupying a slot meant for a word”, and it makes the structure obvious. The dependency tree has no such device and does not need one: it simply makes forgive the csubj, a “clausal subject”, and attaches it to takes like any other subject. The tree flattens what the diagram elevates.

Key terms

Infinitive: to plus a base verb. Carries no tense, so it cannot head a clause. The to is tagged TO, relation aux. She wants to leave. To forgive takes courage.
Infinitive phrase: The infinitive plus its own objects and modifiers, all travelling together as one unit. She wants to leave early. To climb that hill takes an hour.
Pedestal: The stand raising a whole construction into a single slot. Used for infinitives, gerunds and noun clauses alike. To forgive takes courage. — the infinitive subject stands on a pedestal. She likes to swim. — so does an infinitive object.
See: Reed-Kellogg Diagrams, Gerunds, Noun Clauses
xcomp: “Open clausal complement” — the relation for an infinitive completing another verb, with its subject supplied by the main clause. She wants to leave. — leave is the xcomp of wants. They began to sing.
See: Core Arguments

Practice on a real sentence

A complex sentence with embedded clauses. Look at which verb ends up as the root.

“She wondered whether he was sorry he had hurt her.”

Parts of speech

Give every word its coarse Universal Dependencies category.

Words 0/10Attempts 0Correct 0Time 0:00

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

She wondered whether he was sorry he had hurt her.