Verb
(auxiliary) Indicating duty or obligation.
(auxiliary) Indicating advisability or prudence.
(auxiliary) Indicating desirability.
(auxiliary) Indicating likelihood or probability.
Source: en.wiktionary.orgA liar ought to have a good memory. Quintilian
The man who has received a benefit ought always to remember it, but he who has granted it ought to forget the fact at once. Demosthenes
Whoever hammers a lump of iron, first decides what he is going to make of it, a scythe, a sword, or an axe. Even so we ought to make up our minds what kind of virtue we want to forge or we labour in vain. Anthony the Great
In great action, men show themselves as they ought to be, in small action as they are. American Proverb
A gentleman ought to travel abroad, but dwell at home. English Proverb
A liar ought to have a good memory. Dutch Proverb