表達 必須做某事 (Y)，可透過 must do Y、have to do Y、have got to do Y、need to do Y 等，表達 因規定或法律上的責任或義務而必須做某事 (Y)，可透過 must do Y、have to do Y、be obliged to do Y (正式)、be required to do Y (正式)、have a duty to do Y ( 其也可指因道義上的責任或義務而必須做某事 (Y) )、have an obligation to do Y ( 其也可指因道義上的責任或義務而必須做某事 (Y) )、be under an obligation to do Y ( 其也可指因道義上的責任或義務而必須做某事 (Y) )、be under a duty to do Y ( 其也可指因道義上的責任或義務而必須做某事 (Y) )、it is compulsory to do Y、it is mandatory to do Y (正式)、it is obligatory to do Y (正式) 等，表達 別無選擇而不得不做某事 (Y)，可透過 have no choice but to do Y、have no option but to do Y、have no alternative but to do Y、be left with no choice but to do Y、be left with no option but to do Y、be left with no alternative but to do Y 等，表達 因忍不住或控制不住而不得不或非得做某事 (Y)，可透過 can’t help doing Y、can’t help but do Y、can’t but do Y 等，表達 被迫做某事 (Y)，可透過 be forced to do Y ( 或說 be forced into doing Y )、be made to do Y、be compelled to do Y (正式)、be obliged to do Y (正式)、be under pressure to do Y、come under pressure to do Y、be put under pressure to do Y、be pressured into doing Y (美式為主) ( 或說 be pressured to do Y )、be pressurized into doing Y (英式) ( 或說 be pressurized to do Y ) ( pressurized 在英式英文中也可拼為pressurised )、be constrained to do Y (正式) 等，表達 因受到恐嚇或威脅而被迫做某事 (Y)，可透過 be forced to do Y ( 或說 be forced into doing Y )、be made to do Y、be coerced into doing Y (正式) ( 或說 be coerced to do Y )、be bullied into doing Y、be blackmailed into doing Y ( 其也可指因受到勒索或敲詐而被迫做某事 (Y) )、be threatened into doing Y、be intimidated into doing Y、be browbeaten into doing Y 等；此外，表達 覺得有必要做某事 (Y)，可透過 must do Y、have to do Y、feel the need to do Y、feel compelled to do Y (正式)、feel obliged to do Y (正式)、feel impelled to do Y (正式) 等；另外，表達 不必、不需要做某事 (Y)，可透過 not have to do Y、not need to do Y、there is no need to do Y、have no need to do Y、it is unnecessary to do Y ( 或說 it is not necessary to do Y )、needn’t do Y (英式) ( 或說 need not do Y )、be under no obligation to do Y 等。
