presently: is a term of rather vague implications as to the extent of time indicated: the doctor will be here ~.    "马上"和"立刻"都表示时间紧迫，但‌"立刻"强调动作发生的即时性，时间点极短；而"马上"侧重动作发生的近期性，时间跨度可长可短，例如可以说春天马上到了(正确)，但不能说春天立刻到了(错误)。解释中说presently表示的时间范围较模糊，因此翻译为"马上"


shortly: typically implies a following quickly or without avoidable delay: you will recieve the report ~ after the tests are completed.


soon: may imply that the thing narrated or predicted happened or will happen without much loss of time: your sister should be home very ~.


directly: implies something happening with little or a minimum of delay: ~ after graduation he joined the family business.


presently马上: 时间范围较模糊，shortly很快:  没有可以避免的延迟，soon很快: 没有多少延迟，可见更快，directly立刻直接: 最小延迟，可见最快


记忆方法: 1) 首字母PS想成水平，SD想成速度<==立刻            按时间从快到慢directly>soon>shortly>presently     

               2) 立刻的意思是过一小会儿mean after a little while.首字母PS想成水平，SD想成速度<==立刻