1、如果
的话；如果是……的话 in the event that 如果；在……
2、假如
in the event that 假如; 如果,万一的; 在…情况下.
3、万一
... to the effect that 大意是 in the event that 万一，倘若 for fear that 生怕，以免 ...
4、连词
... [earlier;previously] 先前 [suppose;supposing;if;in case;in the event that] 连词,假使 [down;downward] 从高处走向或延伸到低处 ...