Affirmative to Negative

Rule 1 : 'Only/ alone/ merely' Replaced by 'None but (person) /nothing but (things)/ not more than or not less than (number)'
Aff: Only Allah can help us.
Neg: None but Allah can help us.
Aff: He has only a ball.
Neg: He has nothing but a ball,
Aff: He has only ten taka.
Neg: He has not more than ten taka.
Rule 2 : 'Must/ have to' Replaced by 'Cannot but + v / Cannot help+ (v+ing)'.
Aff: We must obey our parents.
Neg: we cannot but obey our parents.
Aff: You have to work hard to succeed in life.
Neg: You can't help working hard to succeed in life.
 Rule 3 :  'Both----and /and' ( if join two words) Replaced by 'Not only ---- but also'
Aff: Both Dolon and Dola were present. 
Neg: Not only dolon but also Dola were present.
Aff: He was obedient and gentle.
Neg: He was not only obedient but also gentle.
Rule 4: Aff:  Everyone/ everybody/every person/ (every + common noun)/all
 Neg: There is no + attached word + but.
Aff: Every mother loves her child.
Neg: There is no mother but loves her child.  Aff: Every flower has a thorn.
Neg: There is no flower but has a thorn.
Rule 5:  'As soon as' Replaced by 'No sooner aux ----- than'.
Aff: As soon as the thief saw the police, he ran away.
Neg: No sooner had the thief saw the police he ran away.
Aff: As soon as we reached school, our class started.
Rule 7 :  Aff: Absolute Superlative degree 
Neg: No other+ attached word+so+ positive form+ as+subject.
Aff: Dhaka is the biggest city in Bangladesh. 
Neg: No other city is as big as Dhaka in Bangladesh.
Rule8 :  Sometimes affirmative sentences are changed into negative by using opposite words. Before the word,  off course 'not' is used.
Aff: I shall remember you.
Neg: I shall not forget you.
Rule 9 :  Always  Replaced by Never.
Aff: Raven always attends the class.
Neg: Raven never misses the class.
Rule 10 : Too ---- to  Replaced by 'so ---that + (can + verb).
Aff: He is too weak to walk.
Neg: He is so weak that he cannot walk.
Rule 11 : 'As - as'  Replaced by 'Not less - than'
Aff: Simi was as wise as Rimi.
Neg: Simi was not less wise than Rimi.
Rule 12 : Universal truth are change by making them negative interrogative.
Aff: The Sun sets in the west.
Neg: Doesn't the Sun set in the west.
Rule 13 : 'Sometimes' Replaced by  'Not + always'
Aff: Raven sometimes visits me.
Neg: Raven doesn't always visit me.
Rule 14 : 'Many' Replaced by 'Not a few'
Aff: I have many friends.
Neg: I do not have few friends.
Aff: Bangladesh has a few scholars.
Neg: Bangladesh doesn't have many scholars.
Rule 15 : 'Much' Replaced by 'not a little
Aff: He belongs much money.
Neg: He doesn't belong a little money.
Aff: Dolon has a little riches.
Neg: Dolon doesn't have much riches.