must, ought to और should ➡ ये तीनों एक जैसे लगते हैं परन्तु इनके प्रयोग में बहुत अंतर हैं-
(1) Must ➡ Highly forceful (legal) - You must follow traffic rules.
(2) Ought to ➡ Less forceful than Must (formal) - Everyone ought to help the poor.
(3) Should ➡ Less forceful than Ought to (informal) - You should help your friend.