意思不同：to：对于、为了、(表示方向)到、向、(表示间接关系)给；too：也、太、而且、很。用法不同：to：表示在某范围之外，两者之间可以互相连接，也可以不连接，可与表示“谈话”“交际”的词连用。to表示交际的动作一般是单向的；too：用于肯定句，too通常位于句末，其前的逗号可有可无。
介词to有哪些用法
在英语中to的用法是比较重要的，一般来说 to 有两种基本用法：
1.做介词，表示“到，向，往”，如go to，fly to，后面跟名词作定语，构成介宾结构。
2.动词不定式的标志，很常见的，如：want to do，be happy to do。
注意有一些看似不定式但实为介词的结构，如 look forward to，pay attention to ，他们后面跟动词的ing 形式作宾语，千万不能跟原形。
其他的如to +do 作定语等等基本都是以上两种用法的延伸。
而to的用法重点主要是作介词，下面讲解to作为介词的用法，大约有20多种
一：表示相对，针对
be strange (common, new, familiar, peculiar, distinct, sensitive,immune, vulnerable, indispensable) to
Air is indispensable to life.
Aircrafts are vulnerable to interference caused by radiation.
This injection will make you immune to infection.
二：表示对比，比较
1：以-ior结尾的形容词，后接介词to表示比较，如：superior ,inferior,prior,senior,junior
The quarrel happened prior to my arrival.
2: 一些本身就含有比较或比拟意思的形容词，如equal，similar，equivalent，analogous
A is similar to B in many ways.
3：表示一些先后顺序的形容词，如：second,subsequent,next,preliminary,preparatory
Subsequent to the war,they returned to their hometown.
4: to也偶尔出现在个别动词之后,与动词形成固定词组,表示比较,如:prefer to,compare to,incontrast to
compare to sth.表示比喻或比拟,而compare with sth.表示比较,如:
World is usually compared to a stage
Compared with his past,he has changed a lot.
Prefer的正确句型是:prefer A to B或prefer doing A to doing B,但当prefer后接动词不定式时,表示比较的介
词to就要改成rather than ,如:
The undaunted soldier preferred death to surrender.
Many people prefer spending money to earning money.
They prefer to pursue careers rather than remain home as house wives.
5: to与及个别的名词构成比较之意,如:alternative
Going to an under water concert is a great alternative to going to dinner.
三: 表示修饰关系
1: 表示回复,反应意思的词,如:answer to question,
solution to problem,response to inquiry,reaction to proposal,reply to letter
2: 表示建筑构件的词汇,如: entry,entrance,approach,access,passage,exit,vent,path
the approach to a bridge引桥
the approach to science
Half of the population was estimated to have no access to the health service.p分页标题e
The access to education 接受教育的机会
The access to medical care 享受公费医疗的权利
3: 表示人物职位和官衔的词,如:assistant to manager, ambassador to Spain, successor to tradition,heir to
throne,deputy to the National People’s Congress
advisor to the Prime Minister
too的用法是什么
1、too一般放于肯定句末,表示“也”。例如：
I know the answer,too.我也知道答案。
注意：否定句末的“也”须用either.
I don know the answer,either.我也不知道答案。
2、too有时可放在句首以便引人注目,达到强调的目的。
Too,the reader will find in this book many interesting pictures.
读者也会在这本书中 发现许多有趣的图片。
3、在第二次否定时,可用also或too代替以加强主语的语势,但其必须放于否定词前。
4、固定句式 too ---- to 太---而不能
The books are too heavy to carry.这些书太重了，搬不动。
