obliged 指有必要做什么事，觉得有义务做某事，如： Don't feel obliged to give teachers gifts.They are not expected. I feel obliged to ask them to dinner.compulsory 指有义务必须要做，如： compulsory courses 必修课 compulsory education义务教育 It is compulsory for all motorcyclists to wear helmets.compelled和forded 都都表示被强迫的。前者也指有必要的，后者多指用暴力迫使，“被迫的，不得已的”（个人觉得没什么区别，只是后者比前者更口语化，用得更普遍），如： I feel compelled to write and tell you how much I enjoyed your book. I was forced to leave my country and make a living abroad.
休普若斯
