同學，學習單字時必須注意形式的變化! 不然口說和寫作寫作時常會犯錯 (e.g. it is very convenience)，錯誤也會逐漸固化，到時候又要花更多的時間去修改這些錯誤。同學也可以用搭配詞進一步牢牢背著單字詞性的變化和他的用法 (e.g., a healthy economy 健康的經濟, economic growth 經濟增長, economical prices 經濟實惠的價格, study economics 學習經濟學) 。
succeed (不及物動詞)
succeed in doing sth. 成功做某事
The students succeeded in passing the TOEFL!
學生們成功通過了托福考試！
The teacher succeeded in helping his students pass the test.
老師成功幫助他的學生通過了考試。
successful (形容詞)
someone/something is successful 某人/某事是成功的
Many Taiwanese citizens feel that ABC has been a successful leader of the Legislative Yuan.
許多台灣公民認為ABC是立法院的一位成功領導者。
Some people claim that ABC’s current president has not been very successful in governing the nation.
有些人聲稱ABC現任總統在治理國家方面並不是很成功。
successfully (副詞)
someone did sth successfully 某人成功地做了某事
-Eric’s wife successfully found and emptied his wallet. His attempts to hide his wallet were unsuccessful.
艾瑞克的妻子成功地找到並清空了他的錢包。他試圖隱藏錢包卻沒有成功。
-The students had successfully completed the project and received an A for their hard work.
學生們成功完成了項目並因他們的努力工作而獲得了A等成績。
success (名詞) somebody have/met with success (in doing something) = uncountable
somebody/something is a success (countable)
當作成功不可數，作成功的人或事時可數。
-In an interview, confidence is the key to success.
在面試中，自信是成功的關鍵。
-Greece’s plan to revitalize its ailing economy has met little success/hasn’t met with much success. 希臘振興其低迷經濟的計劃幾乎沒有成功/沒有取得太多成功。
-There will be a sequel to this movie because it was a big success!
這部電影將會有續集，因為它是一大成功！
successor (名詞) 後繼者, 繼任者; 繼承人[(+to)]
-His father named him as the successor to his company.
他父親指定他為公司的繼任者。
-Who do you think will be party leader’s successor?
你認為誰會是黨領袖的繼任者？
資料來源:
http://oald8.oxfordlearnersdictionaries.com/dictionary/