1. As subject:

Reading is an art. Reading is an art.

2. As object:

When a non-finite verb appears after some verbs, only the gerund can be used as the object, and the infinitive cannot be used.

They went on walking and never stopped talking.

3. As a predicate:

When a gerund is used as a predicate, the subject of the sentence is often a noun expressing inanimate things or a noun clause leading to what. The predicative gerund and the subject usually have an equivalent relationship, indicating the content of the subject. The subject and predicate can interchange positions.

If the subject and predicate in the sentence are both verbs, pay attention to keeping the two verbs consistent in form.

Your task is cleaning the windows. (Cleaning the windows is your task.)

4. As an attributive:

Gerunds as attributives often indicate a certain use of the modified word. Such as:

a walking stick =a stick for walking=a stick which is used for walking. A crutch.

Extended information

The gerund is the same in form as the present participle, both adding -ing to the end of the original form of the verb. In modern grammar, these two forms are regarded as "-ing forms".

Another similarity between these two forms is that they are both changed from verbs. They both retain certain characteristics of verbs. They can both bring their own objects and adverbials, and Form a gerund phrase or a present participle phrase to serve as a sentence component. For example:

1. Speaking in the public, he will surely be very cheerful.

(Present participle phrase, used as adverbial) He is always cheerful when speaking in public places.

2. She hates speaking in the public.

(Gerund phrase, as object) She hates speaking in public places.

Baidu Encyclopedia - Gerund