An English sentence must have at least one subject and one predicate. The subject denotes the person or thing about which something is said.
The subject is usually the first noun or noun phrase in a sentence and it represents the thing that the rest of the sentence is about. The subject may consist of one word or several words but it must still have a noun or pronoun it. The main word in the subject is called the subject-word.

Different kinds of subjects

The subject is always a noun or a word or phrase used as a noun.

Read the sentences given below:

Wisdom is better than riches. (Here the subject is the noun wisdom.)
He has refused to leave. (Here the subject is the pronoun he.)
The disabled are God’s special children. (Here the subject is the adjective the disabled which is used as a noun.)
Swimming is good for health. (Here the subject is the gerund swimming which is used as a noun.)
To err is human. (Here the subject is the infinitive to err which is used as a noun.)

The subject-word is often modified by an adjective or the equivalent of an adjective which is called its attribute.

Kinds of Attributes

A man knocked at the door.
Here the subject-word man is modified by the article a which is called its attribute.

Fresh milk is wholesome.
Here the subject-word milk is modified by the adjective fresh which is its attribute.

More examples are given below.

His face turned pale. (Here the subject-word pale is modified by the possessive adjective his.)
Lincoln, President of America, was assassinated. (Here the attribute is a noun or phrase in apposition to the subject.)
John himself finished the work. (Here the attribute is an emphatic pronoun.)
Barking dogs seldom bite. (Here the attribute is a participle used as an adjective.)

Participles, prepositional phrases, to-infinitives, adjectival phrases can also be used as subject attributes.

Exercise

In the following sentences pick out the complete subject; then separate the subject word and its attribute:

1.    Sweet are the uses of adversity.
2.    Dominic, the grocer, sells sugar and rice in the black market.
3.    His bark is worse than his bite.
4.    The king, generous as ever, pardoned the rebel.
5.    Birds of the same feather flock together.

Answers

1.    Subject – the uses of adversity; subject-word – uses; attribute – of adversity
2.    Subject – Dominic, the grocer; subject-word – Dominic; attribute – the grocer
3.    Subject – his bark; subject-word – bark; attribute – his
4.    Subject-word – the king; attribute – generous as ever
5.    Subject-word – birds; attribute – of the same feather