enough、sufficient、adequate有何差異

差異不大、細微的差異是：
Sufficient 指對某項需要恰能滿足 如 sufficient savings.(足夠的存款)
Enough 比較沒有像sufficient 那麼精準、是一個比較概略的詞。例如：
Do you have enough food? 你食物夠嗎?
Adequate 暗指勉強符合某項需求。例如 The service was adequate. 服務是恰如其份。(沒有特別更好)

原文

sufficient suggests a close meeting of a need <sufficient savings>.
enough is less exact in suggestion than sufficient <do you have enough food?>. adequate may imply barely meeting a requirement <the service was adequate>

參考
http://www.merriam-webster.com/dictionary/sufficient

~~小毛