The gerund:

1. Has tense and voice forms; so the forms being done, having done etc. can not be nouns;

2. Can take a direct object; so “-ing” form followed by a direct object (reading a letter) can not be a noun;

3. Can be modified by an adverb; so “-ing” form modified b an adverb(reading fast) can not be a noun;

4. Can be part of a verbal aspect predicate; so “-ing” form following the verbs to begin, to stop, to go on, to keep, etc. are mostly gerunds.

The verbal noun:

1. Can be used in the plural (bright sayings of her children);

2. Can have an article (the banging of the lift);

3. Can be followed by a prepositional phrase in an attributive function (a faint glimmering of light);

4. Can be modified by an adjective, a demonstrative pronoun or an indefinite pronoun (the bright sayings).

The Functions of the Gerund in the Sentence

The Gerund can be:

The Subject

It	is was		no use useless no good		doing smth
There		is was		no doing smth
Doing smth			does smth did smth will do smth would do smth

e.g. It’s no use arguing.

It was no good objecting.

Talking mends no holes.

There is no hiding these facts.

There was no going back.

The Predicative

The main thing Smb’s wish Smb’s job Smb’s duty	is / was doing smth
to feel like (up to) to be for / against	doing smth

e.g. The main thing is getting there in time.

Her job was looking after the children.

I don’t feel like going to the theatre.

Are you for or against staying there?

Also:

1. part of a compound verbal modal predicate with verbs and verbal phrases expressing modality: intend, expect, want, like, feel like, detest, dislike, can’t help, can’t bear / stand, etc. (She intends going there in summer. He couldn’t help admiring the picture.)

2. part of a compound verbal aspect predicate with verbs denoting the beginning, the duration, or the end of the action such as begin, start, go on, keep on, cease, finish, quit, commence, stop, give up, carry on, proceed, resume, continue, etc. (In the night it started raining. He resumed walking. He kept on looking behind.)

The Direct Object

admit anticipate avoid consider delay deny enjoy escape excuse fancy (imagine) forgive involve mind postpone prevent regret remember resent resist risk suggest, etc. to be worth	doing smth
e.g. The film is worth seeing. He admitted taking the money. Sometimes I enjoy being alone.

The Prepositional Object

to think of to suspect smb of to accuse of to be afraid of to object to to be used to to succeed in to be engaged in to insist on to depend on to apologize for to be grateful for to be responsible for to thank smb for to blame smb for to be clever at to prevent smb from, etc.

doing smth being done having done smth having been done

e.g. He apologized for coming late.

She insisted on being treated like a grown woman.

I hope you don’t object to our singing.

We are engaged in discussing this problem.