The homework tonight is optional; you are under no obligation to do it, but it could be good practice for you.
Teachers have an obligation to correct students' homework as soon as possible.
Customers are welcome to try our new exercise machine for 3 months with no obligation to
purchase.
Divorced fathers are obligated to pay for child support.
My friend told me I didn't have to, but I felt obligated to help him pay for the window he broke while we were playing baseball together.
I'm sure Ted will help you if you need it; he's a very obliging
person.
Certain courses are obligatory for your degree program, and certain others are merely suggested.
Thomas Jefferson once said that if a law is unjust, a man is not only right to disobey it, he is obligated to do so.
It is obligatory for people in Switzerland to learn one
of the country's other national languages, so most Swiss speak two or more languages.
Marian Wright Edelman once said that if you don't like the way the world is, you change it. You have an obligation to change it. You just do it one step at a time.
Phone today for a free, no-obligation estimate on completely repainting your home.
People in Senegal are born into traditional family structures that determine one's rights and obligations.
A Chinese proverb tells us that the first favor is a favor, but the second is an obligation.
We are contractually obligated to sell at a fixed price, no matter what happens to interest rates.
Discussion question: Do you think that the rich countries of the world have an obligation to help poor countries?