这两个单词用来表达强制的意思时，force是动词，compulsory是形容词，用法非常不一样。
下面详细分析一下这两个词。force可以作名词也可以作动词，名词是力量武力的意思，动词是强迫的意思。例句，But the force that was guiding her wouldn't permit her to act on such a thought.但是那股引导她的力量绝不会允许她这么做。/They try to force you to do a rational calculation to justify the cost.他们尝试强迫你做一个理性的估算去为花费找借口。compulsory是形容词，意思为必须做的，比如义务制教育，compulsory education。
