Incorrect: Every one knows this.
Correct: Everyone knows this.

Explanation

Everyone should be written as one word.

Incorrect: He held the bag in the both hands.
Correct: He held the bag in both hands.
Correct: He held the bag in both his hands.

Explanation

We do not use the before both.

Incorrect: Everybody should do some or other work.
Correct: Everybody should do some work or other.
Incorrect: Iron is more useful than any other metals.
Correct: Iron is more useful than any other metal.
Incorrect: Winston Churchill is greater than any other British politicians.
Correct: Winston Churchill is greater than any other British politician.

Explanation

In these comparative sentences we should use a singular noun after any other.

Incorrect: He came a 3rd time.
Correct: He came a third time.
Incorrect: He is in class eighth.
Correct: He is in class eight.
Correct: He is in the eighth class.
Incorrect: He opened the book at six page.
Correct: He opened the book at page six.
Incorrect: This is a portrait of King George the sixth.
Correct: This is a portrait of King George VI.

Explanation

The numbers of kings and queens should be written in Roman characters. Examples are: Elizabeth II, Louis XIV
Ordinal numbers (e.g. first, second, tenth etc.) up to twelfth should be written in words except in dates.
Examples
18th October 2003 (NOT Eighteenth October 2003)
This is the fifth time you have asked the same question. (NOT This is the 5th time …)
Dates should be written as follows: July 7th or 7th July. (NOT 7th of July or seventh of July)
Cardinal numbers up to twelve should be written in words except when telling the time.
Examples
He came at 10 am. (NOT He came at ten am.)
She has seven siblings. (NOT She has 7 siblings.)
Cardinal and ordinal numbers above twelve and twelfth may be written in either words or figures.

Incorrect: He is worst than you.
Correct: He is worse than you.
Incorrect: Mumbai is hot than Delhi.
Correct: Mumbai is hotter than Delhi.

Explanation

Only an adjective or adverb in the comparative degree can be used before than.

Incorrect: A horse is usefuller than a car.
Correct: A horse is more useful than a car.

Adjectives and adverbs having more than one syllable form their comparative and superlative forms by the addition of more and most.