Modals for necessity and suggestion

Describe Necessity

Need can also be used to express necessity or strong recommendation. For example: Describe necessity"Have to" is used to express necessity, and obligation. 
For example: Describe necessityMust: Express necesity or strong recommendation.
 For example:
"Students must study hard to pass the TOEIC" 

Giving suggestion

"Had better" is used to make recommendations or suggestion. 

For example; Giving suggestion"Ought to" is used to advise or make recommendations. 

For example; 
Giving suggestion"Should" is most commonly used to make recommendations or give advice. For example; 

 Video about modals for necessity and suggestion

Exercise 1: Modals:Obligation - Necessity -  Prohibition -Suggestion

Exercise 2: must-should-have to-need

Exercise 3: Have to or must