Ch 1

Modals — Obligation and Advice

Should, ought to, had better for giving and receiving advice.

need to, needn't, don't have to, should
B1 Pre-intermediate

Modals: Obligation and Advice

need to, needn't, don't have to, should
need to
Important but not a law - personal necessity
have to
Rule or law - external obligation
don't have to / needn't
No obligation - not necessary
should / shouldn't
Advice - right or wrong thing to do

No obligation - three ways

I don't have to work on Sundays.
Not required - but I can if I want.
You needn't pay for your food.
Not necessary - I am paying.
You don't need to bring anything.
Same meaning - slightly more informal.
Don't have to, needn't and don't need to all mean it is NOT necessary, but it is allowed.

Need to vs Have to

need to - personal importance
You need to be careful with your passport.Important but ultimately your choice.
have to - rule or law
You have to show your passport at the airport.Legal requirement - no choice.

Summary

need to / have to
Necessary - something that must be done
don't have to / needn't
Not necessary - no obligation
should / shouldn't
Advice - the right or wrong thing to do
// Scroll slide content into view on load (function() { var dk = document.getElementById('slide-deck') || document.querySelector('.slide-deck,.deck-content,.slides-container'); if (!dk) { dk = document.querySelector('.slide'); } if (dk) setTimeout(function() { dk.scrollIntoView({ behavior: 'smooth', block: 'start' }); }, 150); })();