liable 形容词.
①常患有···的（to）：be liable to bad cold 常患重感冒.
②倾向于···的；易于···的；习惯于···的；we are all liable to make mistake occasionally.我们大家有时都会犯错误.
③有偿负责任的；在法律上应负责任的（to,v.-ing）：be liable for damages.有赔偿损失的责任.
For example：You are liable for all damage.
你应负赔偿一切损坏的责任.
liability 名词.
①不可数名词.倾向：liability to disease 易患疾病
②不可数名词.责任,义务：liability to pay tax 纳税的义务 /liability for military service 服兵役的义务
③用作复数.债务；负债：heavy liabilities 沉重的债务.
④可数名词.包袱；缺陷：He is a liability to us.他对于我们是个累赘.
For example：He admitted his liability for the accident.
他承认自己对这起事故应负责任.
obligate 及物动词.
常用被动语态.使···负（道德或法律）责任
For example：I'm not obligated to share every little detail of my life with you.
我没有义务让你知道我生活的每一个小细节.
obligation 名词.
①（意思同duty,responsibility）义务；责任：
a legal(moral)~法律上（道德上）的义务/the~of tax 纳税义务/the sense of 责任感
②可数名词.债务；合约：
③可数名词.恩惠：I feel an to him for his help.对于他的帮忙,我很感激.
固定短语：be under(an)~有义务；欠人情债
put/place sb.under an 使某人负有义务
repay an 报恩
For example：The builder failed to fulfil the terms of his obligation.
营造商未能履行合同的条款.
obligatory 形容词.义不容辞的；必须履行的：
duties on all 人人不可推卸的义务.
For example：It is obligatory for us to obey the laws.
我们必须守法.
onus 名词.
负担；义务；责任
For example：The demographic bonus became a demographic onus.
人口统计上的奖励变成了负担
句酷一下网站可以帮你提供更多的例句.
顺便说一下.这些都是我一点点查字典然后打出来的.希望可以对你有所帮助.