(1)惟恐，以免(for fear that;so that... not)(fml)：They spoke in whispers～they (should，might) wake him. 他们轻声说话，唯恐吵醒他。She took her umbrella～it (should) rain. 她带了雨伞以备下雨。Write the message down～you forget it. 把这口信记下来免得你忘了。

(2)(用于fear，be afraid，be anxious等之后，相当于that)(fml)：She fears～he decide to leave her. 她怕他决定抛弃她。I was afraid～he should come too late. 我怕他来得太晚。