Infinitive and gerund
Infinitive
Definition
An infinitive is the basic form of a verb not associated with a subject or tense.
Construction
Affirmative: 'to' + bare infinitive
to go
Negative: 'not to' + bare infinitive
not to go
'to don't go' 
Note that the bare infinitive is the infinitive without 'to': (not) go
Uses
| As a subject | As a complement | As an object |
|
To be on time is important.
Not to be on time is impolite.
|
The important thing is to be on time.
The important thing is not to be late.
|
We need to be on time.
We promised not to be late. |
Note that as a subject, the gerund is more common than the infinitive.
Gerund
Definition
A gerund is a noun formed from a verb - it is the name of an activity or a state.
Construction
Affirmative: bare infinitive + 'ing'
going
Negative: 'not' + bare infinitive + 'ing'
not going
Note that we sometimes have to double the last letter of the verb or remove the 'e' at the end. Here are some examples:
| swimming | hiking |
| travelling shopping | dancing filing |
Uses
| As a subject | As a complement | As an object |
|
Being in this team has lots of advantages.
Cycling is good exercise.
Not having any free time is terrible.
|
What I like about this job is being in a small team.
My favourite sport is cycling.
The best thing about my job is not having a long journey to work. |
I love being in this team.
I enjoy cycling.
I hate not having enough free time. |