Undergo means pass through "The chemical undergoes a sudden change"; "The fluid undergoes shear"; "undergo a strange sensation" and suffer means 1.Undergo or be subjected to "He suffered the penalty"; "Many saints suffered martyrdom" 2.Undergo (as of injuries and illnesses) "She suffered a fracture in the accident" 3.Experience (emotional) pain "Every time her husband gets drunk, she suffers" 4.Feel unwell or uncomfortable "She is suffering from the hot weather". 5.Be set at a disadvantage "This author really suffers in translation" cowboy...

經受 = undergo suffer = 受難 (or 遭到?) but can also mean 受到(影響) in some cases Usually it means 受難. but sometimes it can be used to mean something more like undergo (受到影響）, but with a negative connotation (like the previous answerer said). In the case where it is used to mean something more like "undergo", it is more literary -- so when you hear it in a conversation it almost always means 受難／慘遭。

'Undergo' emphasises the process, procedure. (强调过程) 'Suffer' almost always has a negative connotation to it. (通常有负面的含义) Good luck.