表示对比关系的词汇和短语主要是unlike，not，but，however，despite，in spite of，in contrast 和while 引导的并列句等。
A good supervisor can recognize instantly the adept workers from the unskilled ones.
该句中并未出现上面提到的表示对比关系的词或短语，但是通过上下文可以判断出句子前后是对比关系，即把熟练工人与非熟练工人区分开。这时我们也能够推断出生词adept的词义，“熟练的”。

2． 根据比较关系猜测词义
同对比关系相反，比较关系表示意义上的相似关系，例如：
Green loves to talk，and his brothers are similarly loquacious.
该句中副词similarly表明短语loves to talk与生词loquacious之间的比较关系。以此可以推断出loquacious词义为“健谈的”。
表示比较关系的词和短语主要是similarly，like，just as，also等。

3． 根据因果关系猜测词义
在句子或段落种，若两个事物、现象之间构成因果关系，我们可以根据这种逻辑关系推知生词词义。例如：
Tom is considered an autocratic administrator because he makes decisions without seeking the opinions of others.
根据原因状语从句的内容，我们可以推断出生词autocratic指“独断专行的”。
There were so many demonstrators in the Red Square that he had to elbow his way through the crowd. 此句为结果状语从句，根据从句的描书“许多示威者”，我们便可推知elbow的词意“挤，挤过”。

4． 根据同义词的替代关系猜测词义
在句子或段落种，我们可以利用熟悉的词语，根据语言环境推断生词词义。例如：
Although he often had the opportunity, Mr. Tritt was never able to steal money from a customer. This would have endangered his position at the bank,and he did not want to jeopardize his future.
作者为避免重复使用endanger一词，用其同义词jeopardize来替代它，由此推知其词义为“使. . . 陷入危险，危及、危害”。
Doctors believe that smoking cigarettes is detrimental to your health. They also regard drinking as harmful.
句中detrimental四个生词，但判断出harmful替代detrimental后，不难推断出其词义为“不利的，有害的”。

三 外部相关因素
外部相关因素是指篇章(句子或段落)以外的其他知识。有时仅靠分析篇章内在逻辑关系无法猜出词义。这时,就需要运用生活经验和普通常识确定词义。例如：
Husband：it’s really cold out tonight.
Wife: Sure it is. My hands are practically numb.
How about lighting the furnace?