Verbs express an action or make a statement about a person or thing.
John gave Sarah a present.
Sarah was very surprised.
A finite verb is a 'working' verb with a subject; it can be any tense. A non-finite verb which is also called in infinitive verb has no subject and can't be in all the tenses.
A non-finite verb can be:
an infinitive walk/to walk be/to be be interested/to be arrested
a present participle walking being being interesting
a past participle walked been interested
Asentence must have at least one subject and finite verb.
A sentence: I woke up early because of the noise from the street.
Not a sentence: Because of the noise from the street.
A sentence: I saw john and Sarah arguing just outside their house.
Not a sentence: Arguing outside their house.
A sentence: I went out to buy the things I needed for the party.
Not a sentence: To buy the things I needed for the party.
Lesson by Tristan, English teacher at EC Malta English school
Decide which of the following are sentences or not: