1. adherence&adhesion
  这两个词都是“粘附的”意思。   
  adherence 用于比喻的意思。例如:His adherence to the strict letter of the law.    
  adhesion 是指物质上的。
    
  2. adjacent&adjoining&contiguous
  这些词都有next to“紧挨”的意思。   
  adjacent “毗邻的,邻近的”,但它们可能并不相互直接接触。  
  adjoining和contiguous 指相互接触,通常之间有一个edge或boundary。
    
  3. admission&admittance
  它们都有“the act of entering”的意思。   
  但admission 用于公共场合。例如:The price of admission to the gallery is£5.   
  admittance 不指公共场合,一般指私人的住所。
    
  4. adopted&adoptive
  adopted “收养的,过继的”   
  an adopted son(daughter) 养子(女);my adopted country 我所入籍的国家;adopted words 外来语。   
  adoptive“收养的”,我们说adoptive parents,但很少说adoptive child;“采用的”,“假冒的”an adoptive courage假充勇敢。
    
  5. averse&adverse
  adverse “不利的,反对的”,用于事,不用于人。adverse weather conditions;an adverse reaction。   
  averse “嫌恶的,反对的,不乐意的”,常和“to”一起使用,而且用否定形式。
    
  6. advise&advice
  advise “劝告”(动词);advice “劝告”(名词)。
    
  7. affect&effect 
  affect “影响”vt. ,它的第二个意思是“假装”,Though she affectes indifference, I knew she was really very upset.    
  effect n. “结果”,“效力”。vt. “产生”,“导致”,它比“to cause, to bring out” 更为正式。His aim was to effect a radical change in the party structure.
    
  8. all ready&already
  all ready 意思是 “completely prepared”   
  already “已经”。He had already had his lunch.
    
  9. altogether&all together  
  altogether (in total) “总共”   
  all together 意思是“in a group”。如:We put the sheep all together in onefield. 这两个词还可以分开。We put all the sheep together in one field.
    
  10. allude&elude
  allude “暗指”,“暗示”,“(婉转)提到”。   
  elude (to avoid or escape) “闪避,躲避”。如:to elude sb. 's grasp 逃脱,没有被逮住;to elude the law 规避法律。The meaning eludes me. 那个意义我摸不透。