We can suggest things with “should” (as in “You should paint your house green”) but what to do if we want to be stronger? “Ought to” is for obligations that are morally desirable or offer objective reasons.
“Ought to” for moral obligations
It transmits a moral duty, as when you refer to something that’s right or ethical: “We ought to follow the law” or “They always ought to protect children”.
“Ought to” for objective reasons
It is also used when there’s reason based on fact (not only your personal opinion): “We ought to go now. The last train leaves in ten minutes”.
Examples
“You ought to help your family when they need you.”
“You ought to call Bill. He had an accident.”
“We ought to safeguard the environment for future generations.”
“You ought to act now. Tomorrow will be too late.”
Use “ought to” carefully
Because ‘ought to’ is quite strong and formal, be cautious when you use it. If the other person doesn’t agree with your reasons, it can sound like you are telling them what to do, which might upset them.
Don’t want to sound so strong?
Would you like to be more polite? You could use “should”, as in “You should finish this before 10AM”. It’s more common and not so strong.
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