| must(noun, verb, work, charge, understanding) |
| naught(noun, adjective, nothingness, zero, nonentity) |
| need(noun, verb, work, charge, understanding) |
| nought(noun, adjective, nothingness, zero, nonentity) |
| should(verb, consider, leave, allow, have) |
| duty(noun, understanding, right, concern, use) |
| obligation(noun, work, charge, right, concern) |
| onus(noun, work, charge, understanding, right) |
| zero(noun, adjective, nothingness, nonentity, nothing) |
| charge(noun, work, understanding, right, use) |
| nothing |
| aught |
| burden(noun, work, charge, understanding, right) |
| business(noun, work, charge, understanding, right) |
| commitment(noun, work, charge, understanding, right) |
| have(verb, bear, endure, want, need) |
| have to(verb, expression, phrasal verb, have, bear) |
| would(bear, must) |
| allegiance(noun, burden, responsibility, liability, obligation) |
| be obliged to(verb, expression, idiom, want, need) |