presently: is a term of rather vague implications as to the extent of time indicated: the doctor will be here ~.


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 will come home ~.


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


presently: 时间长短模糊， shortly: 没有可以避免的推迟，即尽快， soon: 没有大量的推迟，即没多会儿， directly直接: 最小延迟


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>shortly>soon>presently

          2）立刻的意思是过了一小会儿mean after a little while.