Rule 6: The reason is / The reason why
Sentences beginning with ‘The reason is / The reason why’ are connected by conjunction ‘that’ and not by conjunction ‘because’, ‘due to’ or‘owing to’
e.g., The reason of his failure is that he did not study seriously.
The reason why he failed is that he did not study seriously.
Rule 7: As if / As though
As if/ As though shows expressions having imagination or condition; hence Past conditional tenseshould be used with them but not ‘PresentorFuture tense’.
e.g., He behaved as if he were the king!
He behaved me as though he were my son.
Rule 8: Because/ In order that
‘Because’ is used to show Cause ‘In order that’ is used to show Purpose.
E. g., He failed because he did not work hard.
He worked hard in order that he may secure first division.
Rule 9: While is used in two senses-----
(a)To denote ‘time period’.
(b)To denote ‘Togetherness’ or ‘At the same time’
While I was in service, I never saw him.
While there is life there is hope.
Rule 10: Because/ For/ Since
All the three words show causes. There is only one difference, ‘Because’ has maximum force, ‘For’ has minimum and ‘ Since’ lies between them.
I must go because my mother is ill.
He failed because he did not work hard.
He could not catch me since he was lazy.
He cannot be trusted for he takes everything casually.
Rule 11: “THAT”
(A) If principal verb comes in the clause beginning with Interrogative Pronoun or InterrogativeAdverb; ‘than’ is used before that clause.
e.g., I know that what he says is not true.
I promise that when I come next I will bring your book.
‘That’ is hidden in those clauses which are followed by some verbs (e. g., afraid, believe, think, hope, presume, suppose etc.)
e.g.,I believe @ he is right.