英语考试多多少少总是会遇到几个生单词，那么怎样根据上下文句子来猜词呢?
托福阅读揣摩生词法一、利用上下文线索猜测词义
1、根据同义、反义关系猜词
Today‘ s teenagers seem to be more liberal in their ideas than their _______ grandparents.
A. freethinking B. traditional C. old D. happy
traditional与liberal意思相反，故选B。
2、根据句意或段落文章的上、下文猜测词义
Klebold and Harris felt _______ and wanted to revenge against those who disliked playing
together with them or laughed at them.
A. discouraged B. ashamed C. tired D. separated
根据下文的disliked playing together with them判断此处应为“感到孤立”，故选D。
专家解读托福阅读揣摩生词法二、利用构词法猜测词义(利用前、后缀及合成词猜词义)
1、用前、后缀猜测词义
英语中的前缀、后缀构词颇多，且特定的缀往往表示特定的含义，把握住这一点，可起到以不变应万变的效果。
1)He had been overworking and fell ill at last.
overwork是由前缀over-加动词构成，over有“超过、过于”之意，overwork意思是“工作过多，劳累过度”。再如，overburden负担过重，overcharge要价过高，overdo做得过分。英语中常用的
前缀还有：
mis-错，误：misfortune不幸;mislead误导;mismanage处理不当
mid-中央：midnight半夜;midway半路
under-低于：underdone半生不熟的;underestimate低估
anti-反对：antibody抗体;anticyclone反气旋;antifreeze防冻剂
下面划线单词为常见后缀派生词：
1)You must stop dreaming and face reality.(-ty为名词的标志)
2)The country is trying to popularize education. (-ize为及物动词的标志，再如realize， modernize)
2、利用合成词猜测词义。
Family members take turns choosing a special activity for the evening， and everyone partakes in for fun.
根据短语构成及上下文意思看，此处partakes in相当于takes par...