1、 distinctive和distinct

　　distinctive"有特色的"，"独特的";

　　distinct"清楚的，明显的";

　　a distinct smell of alcohol on his breath;the distinctive stripes of the zebra.

　　2、 dual和duel

　　dual"二重的";

　　dual personality双重人格;dual control双重管辖;

　　duel"决斗，竞争";

　　fight a duel with sb.与某人决斗;

　　challenge sb. to a duel向某人提出决斗;

　　a duel of wits斗智

　　3、 eatable和edible

　　eatable a."可食用的，可吃的";n.[pl.]"食物、食品"

　　edible a."适合食用的，可以吃的";n.[pl.]"食品"

　　在指吃的时候二者可通用：

　　The toast was burnt and barely eatable/edible.

　　但在其他情况下不一样：

　　If something is eatable，it may be eaten(though it may not be safe or desirable to do so);but，if something is edible it is safe to eat.

　　4、 economical和economic

　　economic"经济学的，经济上的"an economic survey of Scotland苏格兰经济调查;an economic blockade经济封锁;economical"节俭的，经济的";He's had to learn to be more economical now that his only income is a small pension.