immediately、instantly、presently、directly、shortly、soon、at once与right away这些副词或副词词组均有“立刻、马上”之意。
immediately : 指做完一件事后，立即就做另一件事，中间一般没有明显的时间间隔。
- We really ought to leave immediately.
我们真的应该马上就走。 - The purpose of the meeting wasn't immediately obvious.
会议的目的并不明确。
instantly : 指恰恰就在此刻，一秒钟也没耽误。
- Both drivers were killed instantly.
两名司机当即丧生。
presently : 指不久、即将，一种比较过时的说法。
- The room was hot and presently her eyes grew heavy and she began to feel sleepy.
屋子里很热，一会儿她就觉得眼皮发沉昏昏欲睡。
directly和immediately同义，指毫无迟疑。
- Dr Schwarz will be with you directly.
施瓦茨医生很快就到。
shortly和soon同义，指动作发生或完成的速度之快。
- We will shortly be arriving in King's Cross Station.
我们马上就要到国王十字车站了。
soon : 常用词，指行动快，完成速度快。
- She'll soon be here./She'll be here soon.
她很快就到。 - It will soon be impossible for foreigners to enter the country.
不久以后，外国人就不能进入这个国家了。 - The sooner we leave, the sooner we'll get there.
我们出发得越早，到那儿也就越早。
at once : 口语中常用，语气强烈，指时间紧迫，一刻也不能耽误。
- They all started talking at once.
他们同时开始讲起话来。
right away : 主要用于美国英语，语气稍弱于at once，强调动作迅速。
- You'd better leave right now.
你最好马上离开。
