(1)又，也(in addition;also;moreover)(通常放在句尾)：She can dance and sing～. 她会跳舞也会唱歌。He is hungry，and(is)thirsty～. 他又饿又渴。My brother enjoys swimming and likes cycling～. 我弟弟喜欢游泳，又喜欢骑自行车。My husband likes cycling，and I do～. 我丈夫喜欢骑自行车，我也喜欢。

(2)太，过于(to a greater extent，or more than is required，suitable)(通常用于形容词和副词的前面)：take things～seriously 把事情看得过于严重;drive～fast 开车太快了;arrive～late 来得太晚了;(dress) be～small for sb (衣服)对某人来说太小了;be～old/weak for the job (work) 年纪太大/身体太虚弱，不适合做这项工作(工作);It's～late to do anything now/cold to play outside. 天太晚了，现在什么事情都做不成了/天太冷了，不能在外边玩了。It's～hot a day to work/big an apple for him to eat. 天气太热，无法工作/苹果太大，他吃不了。There's been～little rain/snow lately. 近来雨/雪下得太少了。

(3)非常，很(extremely;very)：not～sure/smart 不十分清楚/不很潇洒;be only～willing to be of service 非常乐意帮忙;be only～pleased to hear from sb further 欢迎某人再来信;

(4)表示惊奇(indeed)：There was frost/snow last night，and in May～! 昨天晚上下霜/雪了，现在可是5月呀!You will～do it! 你确实想做这件事呀!

【用法】 1)一般来说，too +形容词，可用作pred，如：The room is too small.(这房间太小。)也可用作名词的attrib，如：It's too small a room.(这是一间蜗居。)注意，作attrib 时，仅可用不定冠词(注意其位置)，不可用定冠词，如：*the too small room; 2)too 可以修饰作形容词用的ed 分词，如：He was too tired to go any further.(他太疲倦了，再也走不动了。)但如果ed 分词行为意义很强，正式文体中，一般要用too much，如：He was not too much bothered by her criticisms.(她的批评并未使他感到太大的困扰。)

【辨异】too 与also、either和短语as well的区别见ALSO。