從雅思閱讀考試的題型特性出發，可以歸類為主旨題和細節題。其主旨題考核的是考生的總結歸納能力，細節題則相應考核定位查詢能力。下面是小編為大家整理收集的關於雅思閱讀同義詞替換的4大原則，希望對大家有所幫助。
1詞性之間的替換
詞性的替換主要是指題目中的關鍵資訊與原文中的內容在詞性上做了變化而已。這樣的替換相對來說，難度係數偏低，只需要考生能夠辨認出相同的詞根即可。
Example 1：
Cambridge8，Test3中Q35：Through mutations, organisms can 35 better to the environment.首先通過mutation一詞將此填空題在原文定位到第C段”Because of changes in the genetic material (mutations) these have new characteristics and in the course of their individual lives they are tested for optimal or better adaptation to the environmental conditions.”然後尋找空後關鍵詞better to，根據空格前的情態動詞can推測空格處只能填一個動詞，而且是原形，還要能和to搭配。這麼一來，這句話裡只有一個對應詞比較合適：adaption，將其變形為動詞adapt即可。
Example 2：
Cambridge6，Test2中Q17Q18：This is largely due to developments in 17 , but other factors such as improved 18 may also be playing a part.定位到原文第四段”Clearly, certain diseases are beating a retreat in the face of medical advances. But there may be other contributing factors. Improvements in childhood nutrition in the first quarter of the twentieth century….”表明有些疾病是被medical advances打敗的。根據空格前的介詞可以判斷17題缺一個跟developments相關的名詞。正確選項是medical的同根詞M(medicine)。而18題是一個被improved修飾的名詞，原文中improvements是它的同根詞，所以答案是選項J (nutrition)。
這樣的替換，即使單詞是陌生的，卻可以通過相同的詞根或詞形來幫助考生去挑選答案。要想掌握好這樣的替換，也就要求考生儘可能地去多熟悉英語詞彙中各種詞根與詞綴的應用。
劍橋閱讀中出現的同根詞變身：
ability → able
diabetic → diabetes
secrete → secretions
fertilise → fertilisers
creativity → creative
investigative → investigate
prefer → preference
emit → emission
predictability → predicted
2同義詞/近義詞之間的替換
同義詞替換是指考題與原文中的關鍵內容用同義詞進行一種互換。此類替換佔據同義替換現象的大部分內容，而且幾乎所有的題型都會有這樣的替換現象。且大量常見的詞都會主要是以名詞與動詞為主。
Example 3：
Cambridge6，Test4的Q9：Kim Schaefer’s marketing technique may be open to criticism on moral grounds.在原文第三段中定位到”Selling pharmaceuticals is a daily exercise in ethical judgment,”其中ethical即為原文中moral的同義詞。
考生只需要在平時增加詞彙量時有意識地去注意一些常見同義詞，雅思閱讀的解答也就變得簡單很多了。其實嚴格意義上來講，同義詞應該還包括一些常用片語或短語之間的一種互換。
Example 4：
Cambridge7，Test4的Q19：Between 1940 and 1959, there was a sharp decrease in Alaska's salmon population.此題為是非判斷題。利用between 1940 and 1959定位到原文第4段Between 1940 and 1959, overfishing led to crashes in salmon population so severe that in 1953 Alaska was declared a federal disaster area. 原文中的crashes與題幹中的sharp decrease屬於近義詞(語義相同的詞)之間的替換。
Example 5：
Cambridge6，Test1的Q38Q39：In recent years, many of them have been obliged to give up their 38 lifestyle, but they continue to depend mainly on 39 for their food and clothes.定位到原文D段：Over the past 40 years, most have abandoned their nomadic ways and settled in the territory’s 28 isolated communities, but they still rely heavily on nature to provide food and clothing.題幹中提及被迫放棄什麼生活方式，因此要求填一個形容詞來修飾lifestyle。而時間狀語in recent years是定位詞。按順序原則，原文的時間狀語over the past 40 years正好跟in recent years對應，abandon與give up，ways和lifestyle對應，答案便是abandon後面的賓語ways的修飾語nomadic。同時判斷depend on後面需要填一個名詞，即依靠什麼東西。而後面的food and clothes是非常好的定位詞。很快可以在原文中找到對應depend on的rely on,而後面又有food and clothes。因此可以很清楚地判斷出rely on的賓語nature就是答案。
劍橋中出現的同義詞/近義詞
change → shift / revision
overstate → exaggerate
target → goal
comments → feedback
performance → achievement
metropolitan → city
world → global
perceive → sense / feel
calculate → measure
resemble → look like
link to → associated with
expert → scientist
hard to find → elusive
3.否定加反義之間的替換
Example 6：
Cambridge7，Test1的Q33：In the follow-up class, the teaching activities are similar to those used in conventional classes.根據順序原則以及follow-up可以定位到原文第6段。Such methods are not unusual in language teaching.題幹中similar to和原文的not unusual屬於否定加反義之間的替換。
Example 7：
Cambridge8，Test3的Q38：In principle, it is possible for a biological system to become older without ageing.可以定位到原文第三段Thus ageing and death should not be seen as inevitable, particularly as the organism possesses many mechanism for repair.題幹中possible是原文not inevitable的否定加反義替換。
劍橋閱讀中出現的否定加反義替換
downward → not rising
not traditional → radical new approaches
with no rain at all →droughts
4.上下義詞之間的替換
所謂上下義，是指替換的詞語之間通常有一種從屬關係。在雅思的閱讀中這類替換往往出現在段落配對題之中，題目中給的是一個具有屬性或者是表示概念的詞語，而在原文中出現的替換詞卻是一個具體或者是細節的資訊，考察考生對這兩者之間從屬關係的配對。
Example 8：
Cambridge6，Test3的Q28：Studies show drugs available today can delay the process of growing old。此題為是非判斷題，定位詞為“drugs”，在原文中定位，我們能在文章第一段找到“As researchers on aging noted recently, no treatment on the market today has been proved to slow human aging—the build-up of molecular and cellular damage that increases vulnerability to infirmity as we get older”。原文中treatment即為題幹中drugs的上義詞。
Example 9：
Cambridge7，Test1的Q5：early military use of echolocation 。此段落資訊配對題在原文定位的句子是“it was only a matter of time before weapons designers adapted it for the detection of submarines.之所以這樣定位，就是原文中weapon一詞作為題幹中military的下義詞出現。
劍橋閱讀中出現的上下義詞替換
chemical → fertilizer and pesticide
military → Second World War
body language → gesture
farming → grow plants and herd animals
environment → light, sound and warmth