It wasn't necessary for me to walk to work as he gave me a lift.	I didn't need to walk to work as he gave me a lift.
There's no need to correct the tests today.	Don't bother to/It isn't necessary to/You needn't/You don't need to ...correct the tests today.
He isn't obliged to tell you the truth.	He needn't//He doesn't need/have to ...tell you the truth.
It is important for you to learn to drive.	You need/have to learn to drive.
Are tests compulsory at this school?	Do you have to take tests at this school?
Senior students don't have to take tests.	It's optional for senior students to take tests.
It is against the rules to write your answers in ink.	You mustn't write your answers in ink.
It is forbidden to smoke in most public places.	You mustn't smoke in most public places.
He couldn't go out because it was raining.	The rain prevented him from going out.
It is advisable to speak politely to your teachers.	You shouldn't/You had better ...speak politely to your teachers.
It would be a good idea to go on a diet.	You had better/You should to/You ought to/It is advisable to ...go on a diet.
Why didn't you consult your lawyer?	You should have consulted your lawyer.
Let's work out the details.	Shall/Why don't ...we work out the details?
Shall I help you with the dishes?	Would you like me to help you with the dishes?
Could you come on Monday?	Would Monday be convenient for you to come?/How does coming on Monday suit you?
May I borrow your car?	Do/Would ...you mind if I borrow your car?//Could I borrow your car, please?
Would you like to open a bank account?	Would it interest you to open/Would you be interested in opening/How would you feel about opening a
She is unlikely to pass her exams.	It is unlikely/not likely that//It's doubtful whether ...she'll pass her exams.
She is unlikely to pass her exams.	There's litlle likehood/possibility of her passing her exams.
He is likely to win the prize.	It is likely that he will/It is very possible that he will/He could certainly ...win the prize.
He is likely to win the prize.	There is every likehood that he will win the prize.