Infinitivals

Bare infinitival

Practical rule

Bare infinitivals occur mainly after:

• modals → can go, must leave

• do → do go, did leave

• make/let → made him go, let her stay

• perception verbs → saw him run

• help → helped him finish

• semi-fixed expressions → had better go, would rather stay

Outside these environments, modern English normally requires to:

I want to leave.

I want leave.

She decided to go.

She decided go.

Usage

Construction / licenser	Example	CGEL analysis	Typical use
Modal auxiliaries	She can swim.	Modal + bare infinitival complement	Ability, possibility, necessity, prediction
Dummy auxiliary do	I do know the answer.	Do + bare infinitival complement	Emphasis, negation, inversion
Causative make (active)	They made him apologise.	NP + bare infinitival clause	Cause someone to act
Let	She let him leave.	NP + bare infinitival clause	Allow someone to act
Perception verbs	I saw him cross the road.	Object + bare infinitival clause	Direct perception of an event
Help	She helped me carry the bags.	Help + bare infinitival clause	Assistance
Had better	You had better leave.	Semi-modal + bare infinitival complement	Strong advice
Would rather	I would rather stay home.	Semi-modal + bare infinitival complement	Preference
Why + bare infinitival	Why worry about it?	Elliptical interrogative construction	Rhetorical question
Come/go + bare infinitival (informal)	Come see what happened.	Serial verb-like construction	Movement followed by activity

To infinitival

Practical rule

Use to-infinitivals especially for:

• Goals and intentions → plan to, want to, decide to

• Potential or evaluation → likely to, difficult to, good to

• Actions viewed as possible or projected → the next step is to analyse, the person to contact

• Purpose → went there to help

• Explicitly packaging an event as an idea/object of thought → the decision to leave, the ability to communicate

Main semantic tendencies

Use	Typical interpretation
Desire/intention	want to leave, plan to travel
Potential/possibility	likely to happen, able to work
Future orientation	decision to act, opportunity to improve
Purpose	went out to buy food
Evaluation	difficult to explain, foolish to ignore
Content	claim to know, ability to communicate

Usage

Construction / use	Example(s)	CGEL analysis	Typical meaning / use
Modal-like adjective + to-infinitival	She is likely to win.	Adjective complement	Possibility, evaluation, expectation.
Extraposed subject	It is important to understand this.	Extraposed subject clause	Evaluation, necessity.
Noun + to-infinitival complement	His ability to communicate is impressive.	Complement of noun	Potential or action associated with the noun.
Noun + to-infinitival modifier	The decision to leave was difficult.	Post-head modifier of noun	Intended action or content associated with the noun.
Verb + to-infinitival complement	She wants to leave; They decided to stay; He refused to answer; She managed to finish.	Catenative complement	Desire, decision, volition, achievement, etc.
Subject-control verb	I hope to see you soon.	Subject-controlled infinitival	Matrix subject is understood as the infinitival subject.
Object-control verb	They persuaded him to leave.	Object-controlled infinitival	Matrix object is understood as the infinitival subject.
Passive + controlled infinitival	He was expected to arrive early.	Raised/control-like passive construction	Reporting or expectation.
Infinitival subject	To travel alone can be challenging.	Subject clause	General statements.
Predicative complement	My goal is to become a writer.	Subject complement	Identity, purpose, planned action.
Object complement	I found the book to be useful.	Complex catenative construction	Assessment.
Noun complement (content)	The claim to have solved the problem was false.	Complement of noun	Content of the noun.
Noun modifier expressing purpose	a machine to cut paper	Post-head modifier	Intended function.
Relative-like infinitival modifier	the first person to arrive	Non-finite relative clause	Identifies a participant.
Purpose adjunct	She went outside to get some air.	Adjunct infinitival clause	Goal or purpose.
Result adjunct	He trained hard, only to lose the final.	Supplementary infinitival clause	Unexpected result.
Attitude/evaluation construction	She was foolish to ignore the warning.	Supplementary infinitival clause	Speaker’s evaluation.
Reason/explanation	I was surprised to hear the news.	Supplementary infinitival clause	Cause of an emotion or reaction.
Interrogative infinitival	I don’t know what to do.	Non-finite interrogative clause	Unresolved question or choice.
Passive infinitival	The car needs to be repaired.	Passive to-infinitival	Passive event.
Perfect infinitival	She seems to have forgotten.	Perfect to-infinitival	Prior event.
Progressive infinitival	He appears to be working.	Progressive to-infinitival	Ongoing event.
Perfect progressive infinitival	She seems to have been waiting.	Perfect progressive to-infinitival	Earlier ongoing activity.
for + subject infinitival	It is unusual for him to complain.	To-infinitival with overt subject	Explicit infinitival subject.