'aim' 是你希望做到或成就的事情:
'I aim to be a millionaire by the age of thirty.'(我想在30岁之前成为百万富翁。)
'achieve' 指的是成就你希望做到的事情：
'I have achieved most of my goals for this year, but I still aim to get better at speaking English.' (我做到了今年大多数目标，但我还想英语口语更棒一点。)
名词'achievement' 指的是你成就的事情或取得的成绩：
'She has many achievements in the world of science.' (她在科学领域里取得了很多成就。)
'He says his greatest achievement is his two lovely daughters.' (他说他最大的成就是他两个可爱的女儿。)