相同点：都可以作形容词、代词，如(都是词霸上的例子)
1. Both guests have arrived. Both the books are torn. Both her fingers are broken.
All the windows are open. Deal all the cards.
注意：both和all作形容词修饰名词，在有冠词的情况下放在冠词前，这一点和其他形容词不同。例如，all the world 和 the whole world
2. Both were candidates. We are both candidates. Both of us are candidates.
All that I have is yours. We are all Chinese. All of us are sick.
3. 与否定词“not”连用时只表示部分否定，而且不要被“not”灵活的位置迷惑，应理解为“不是所有的…都…”
不同点：both可作连词，all可作副词，如
1. both men and women; an attorney well regarded for both intelligence and honesty.
2. a room painted all white; directions that were all wrong. 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”
