Non-finite verbs

Read the following sentences:

1. John thinks that he is a great artist.
2. I wish to learn English.

In sentence 1, the verb thinks has a subject. Its form is determined by the number and person of its subject, namely John. Verbs which are thus limited by number and person of their subject are called finite verbs. Note that all verbs in the indicative, imperative and subjunctive moods are finite, because they have subjects and are limited by the number and person of those subjects.
In sentence 2, the verb wish is finite, because it has a subject and is limited by the number and person of that subject, namely I. But to learn has no subject and is not limited by the number or person of the subject. It is used without any change whatever be the subject of the sentence.
Compare:

• You wish to learn.
• I wish to learn.
• He wishes to learn.
• They wish to learn.

As you can see, the verb wish changes its form according to the number and person of the subject. When the subject is a singular noun it becomes wishes. The verb to learn, however, remains the same. It is therefore described as a non-finite verb and its specific name is an infinitive.
There are three kinds of non-finite verbs:
The infinitive
Examples are: to learn, to write, to work, to break, to speak etc.
The participle
Examples are: learning, learned, writing, written, working, worked, breaking, broken, speaking, spoken etc.
The gerund or verbal noun
Examples are: learning, writing, working, running, speaking etc.

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