both可作连词,all可作副词,如1.bothmenandwomen;anattorneywellregardedforbothintelligenceandhonesty.2.aroompaintedallwhite;directionsthatwereallwrong.all能修饰形容词2.数量上:both固定是“两、双”,而all表示“三个或三个以上”