Must is used
1. To Show order or compulsion
A servant must obey his master.
You are getting late, you must hurry up.
She must weep or she will collapse.
One must work hard or fail.
2. To show certain belief
All must perish one day.
Death must come one day.
You must buy a new cycle.
We must do our duty.
5. Strong determination
We must fight for our rights.
6. Prohibition - must not
You must not open the letter without my permission.
Ought to is used
1.To show sense of moral duty from within
We ought to help the needy.
You ought to respect your seniors.
2. Strong probability
India ought to win the match.
Let us see what we have learnt
1. She _________ do it at every cost.
2. You _________ work hard or face consequences.
3. Every one _________ get old.
4. You _________ practise what you preach.
5. The boys _________ work hard to succeed.
6. The match _________ start on time.
7. They _________ finish this assignment before they leave.
8. You _________ to guide the old man there.
Check yourself here
1. Must, 2. Must, 3. Must, 4. Ought to, 5. must, 6. Must, 7. Must, 8. Ought to.