Sometimes Demonstrative Pronouns are used indefinitely. That is that these pronouns are not used as substitutes for some Noun expressly mentioned, but for some Noun understood or implied.
(a) None but fools behave like this.
(b) All were drowned.
(c) Some are born great.
(d) They say that he is a genius.
(e) Anybody can do that.
(f) Nobody was there to bid her farewell.
(g) Few escaped unhurt.
(h) Many are called, but few are chosen.
(i) Do good to others.
(j) What is everybody's business is nobody’s business.
(k) Everyone wants to be healthy and happy.
One : We have already seen that this pronoun is often used in the sense of any person or every person.
(a) One should take care of one's health.
(b) A man (any and every man) should take care of his health.
The above two sentences convey the same meaning.
Whenever ONE is the Subject to a Verb, it must be followed by ONE…not by HE. Thus we cannot say….One must take care of his health. The correct way to say is…. One must take care of one’s health
The noun NONE (NO ONE) should be followed by a Singular Verb, when it is Subject of the sentence.
(a) None but the brave deserves the fair. (Dryden)
When several persons or things are spoken of, the Verb can be made Plural by attraction.
(a) None of my lost books were found.
(b) None but fools have ever believed in ghosts.
In such phrases as those shown below, the word IT gives emphasis to the Noun or Pronoun following.
(a) It was I who told you that.
(b) It was my uncle who died yesterday.
Sometimes the Noun, for which the word IT is used, can be understood from the context.
(a) It is raining = rain is raining or falling.
(b) It is blowing hard = the wind is blowing hard.
(c) It is fine today = the weather is fine today.
(d) It is hot = the air is hot. It is cold = the air is cold.
(e) It is still early = the hour is still early.
(f) It is two miles from here = the distance is two miles.
(g) It was autumn = the season of the year was autumn.
(h) It is useless to be here = the state of being here.
(i) It is advisable to take your mother with you = ( the action of taking your mother with you).