Verbals

Gerunds

A gerund is an -ing verb form used as a noun: Rescuing the kitten took an hour. It fills a noun’s place, but it can still take an object, like a verb. English often uses a gerund where Spanish uses an infinitive, so gerunds are worth learning to recognise and to draw.

What you’ll learn

Tell a gerund from a participle and from a progressive verb
Draw a gerund on its step, on a pedestal or after a preposition
Place a gerund phrase as a subject, a direct object or the object of a preposition
Keep a gerund's own object attached to it, in the diagram and in the tree
Use a gerund, not an infinitive, after a preposition and after verbs like enjoy

Gerund, participle or progressive verb?

An -ing word can do three different jobs, and it is spelled the same way in all three. Only its job tells you which one it is.

Gerund — used as a noun. Rescuing the kitten took an hour.
Participle — used as an adjective. The rescuing party arrived. After keep, the -ing word is a participle too: in she kept talking, talking is a predicate adjective. Many textbooks list keep + -ing with the gerunds instead. See Participles.
Progressive verb — part of the verb phrase. She was rescuing the kitten. See Verb Phrases and the progressive.

The gerund step

A gerund gets its own symbol, a small step: a horizontal line, a short drop, then a second horizontal line. In a slot on the base line, such as the subject or the direct object, the step stands on a pedestal. After a preposition it needs no pedestal.

The gerund is written whole, on a slant across the step: it starts above the upper line and ends above the lower one. The two levels are a visual way of saying this began as a verb and is now used as a noun. Nothing else in a diagram has this shape.

Find the main verb
In Rescuing the kitten took an hour, the main verb is took.
Ask what took an hour
The answer is the whole phrase rescuing the kitten, so the phrase is the subject.
Draw the step on a pedestal
Write Rescuing on a slant across the step, and stand the step on a pedestal in the subject slot, left of the long vertical line.
Give the gerund its own object
The kitten is what was rescued, so it goes on the step’s lower line, after a half vertical. It does not go after took.

“Rescuing the kitten took an hour.”

Reed-Kellogg — the stepped gerund symbol on a pedestal

csubj Clausal subject
det Determiner
dobj Direct object
ROOT Root of the sentence

Dependency — csubj, with its own dobj hanging below

Comparing the two views

The diagram shows both sides of a gerund at once. The step says it is a verb used as a noun, and the pedestal puts it in the subject slot. The tree has no special symbol. It labels Rescuing csubj of took, a kind of subject; the verb side shows only because kitten hangs from it as its dobj. A gerund alone as the subject usually gets nsubj, like a noun.

Gerund as an object

A gerund fills any slot a noun could. As a direct object it sits on its pedestal in the object position, after the half vertical: He avoids driving at night.

“He avoids driving at night.”

Reed-Kellogg — the gerund in the object slot, with its own phrase

nsubj Nominal subject
ROOT Root of the sentence
xcomp Open clausal complement
prep Prepositional modifier
pobj Object of preposition

Dependency — the phrase attaches to the gerund, not the main verb

Comparing the two views

Both views attach at night to driving, not to avoids: the driving happens at night. The diagram hangs the phrase from the gerund’s lower line, and the tree makes driving the head of at. The labels differ. The diagram and the Roles exercise call the gerund a direct object. The tree labels it xcomp, the label visit gets in She hopes to visit Lisbon on the Infinitives page. Sometimes the parser says dobj instead.

A gerund is also very common after a preposition: tired of waiting, good at drawing. There it is the object of the preposition, and it needs no pedestal. Its step starts at the foot of the preposition’s slanted line.

“Nina is good at drawing.”

Reed-Kellogg — after a preposition, the gerund step has no pedestal

nsubj Nominal subject
ROOT Root of the sentence
acomp Adjectival complement
prep Prepositional modifier
pcomp Complement of preposition

Dependency — drawing is the pcomp of at, not its pobj

Comparing the two views

The diagram keeps the step, so drawing still shows that it is a verb used as a noun. But there is no pedestal: the step starts where the line of at ends. The tree labels drawing pcomp, not pobj: the label for a verb form after a preposition. The Roles exercise boxes drawing as Object of preposition and Gerund phrase.

A gerund can also fill the other noun slots:

Predicate nominative: His basketball strong points are rebounding and blocking shots.
Objective complement: he doesn’t consider that lying.
Appositive: It is usually delightful listening to children at play.

The Roles exercise gives a gerund two labels. One names its slot: Subject, Direct object, Object of preposition and the rest. The other is Gerund phrase, even for a single word (He enjoys cooking).

The labels appear only when the parser recognises the gerund, and it does not always. It reads listening in the last example as a participle. It reads are rebounding in the first as a progressive verb, as it usually does with a gerund after be. In Marta’s job is teaching, the Roles exercise boxes is teaching as one verb phrase, and the Aspect filter calls it progressive.

Common mistakes

A base form after a preposition. Spanish says gracias por ayudarme, but after a preposition English needs the -ing form: Thanks for helping me, not Thanks for help me ✗.
Reading to as the infinitive marker. In look forward to and be used to, the to is a preposition, so a gerund follows it: I look forward to meeting you, not to meet you ✗. See the TO tag.
An infinitive after enjoy, avoid, finish, mind or suggest. These verbs take a gerund as their object. Spanish uses an infinitive here (evito comer tarde), but English says I avoid eating late, not I avoid to eat late ✗.

Quick check

What job does cleaning do in each sentence: gerund, participle or progressive verb? (a) Diego was cleaning the kitchen. (b) Diego hates cleaning the kitchen. (c) A man cleaning the kitchen waved at us.
Answer
(a) A progressive verb: was cleaning is the verb phrase, be + -ing. The swap test fails: Cleaning the kitchen was Diego ✗. (b) A gerund: Diego hates it still works, so cleaning the kitchen is the direct object of hates. (c) A participle: the phrase tells you which man, like an adjective, and A man it waved at us ✗ does not work.
In Fixing the bike took an afternoon, which noun phrase is the gerund’s object, and which is the object of took? Where does each one go in the diagram?
Answer
The gerund’s object is the bike: it is what was fixed. It goes on the step’s lower line after a half vertical, and the step stands on a pedestal in the subject slot. The object of took is an afternoon, so it goes after took on the base line. The tree agrees: bike is the dobj of Fixing, and afternoon is the dobj of took.
A student writes Santiago is interested in learn Italian. Correct the sentence. How is the corrected word drawn, and what does the tree call it?
Answer
Santiago is interested in learning Italian. After a preposition, English uses the -ing form, a gerund; Spanish uses the infinitive (interesado en aprender). In the diagram, the step for learning starts at the foot of the slanted line that carries in, with no pedestal. Italian goes on the step’s lower line as its object. The tree labels learning the pcomp of in, not its pobj.
Is cooking a gerund or part of a progressive verb in Diego’s hobby is cooking? How can you tell, and what will the app show?
Answer
A gerund, the predicate nominative. Swap the words before and after is: Cooking is Diego’s hobby still makes sense. With a progressive verb the swap fails: Diego is cooking → Cooking is Diego ✗. The parser reads both sentences the same way, so the Roles exercise boxes is cooking as one verb phrase and the Aspect filter calls it progressive. A traditional diagram draws such a gerund on a pedestal after the backslash.

Key terms

Gerund: An -ing verb form used as a noun. The name is a false friend: the Spanish gerundio is never a noun, and where English uses a gerund, Spanish uses the infinitive. The parser usually tags a gerund VBG, the same tag as a participle, so the tag cannot tell them apart; the word’s job can. A gerund alone as the subject is often tagged NN instead, like Swimming in the first example. Swimming keeps her fit. He enjoys cooking.
See: Verbs & Auxiliaries · Participles
Gerund phrase: The gerund plus its own objects and modifiers, filling one noun slot together; a lone gerund is a one-word gerund phrase. The Roles exercise pairs it with the slot it fills — Subject, Direct object, Object of preposition. Rescuing the kitten took an hour. She dislikes waiting in queues.
Verbal: A verb form used as another part of speech. The three are infinitives, gerunds and participles. She wants to leave. — an infinitive. Swimming keeps her fit. — a gerund. The whistling kettle woke us. — a participle.
See: Infinitives · Participles
csubj: “Clausal subject” — the relation when a whole construction, rather than a single noun, is the subject. Rescuing the kitten took an hour. — Rescuing is the csubj of took. Whoever arrives first will unlock the door.
See: Core Arguments

Practice on a real sentence

None of the practice sentences has a gerund yet. This one practises the verb side of a gerund: a verb with its own object, as the kitten is the object of Rescuing above. Here two verbs share the lawn, but in a tree a word has only one head. Which verb does the tree make the head of lawn?

Loading the practice sentence…