While I admit his good points, I can see his shortcomings. 尽管我承认他的优点，但我还是能看到他的缺点。
“既然”，相当于since
e.g. I'd like to get it settled today while we are at it.
既然我们着手干了，我想今天就把它解决掉。
当while从句中的主语与主句的主语一致，且含有be的某种形式时，从句中的主语连同be可同时省略。
While listening to the radio, she fell asleep. 她在听收音机时睡着了。
While in London, he studied music and painting. 在伦敦时，他学习音乐和绘画。
conj.
althoughwhereasthoughasbut
n.
minutecycleperiodoftime
vt.
spendwearyout
1.We must strike while the iron is hot.趁热打铁。
2.While she was listening to the radio,she fell asleep.
她听着收音机睡着了。
（2）引起让步状语从句，意思是“虽然…但是…。”、“尽管…但是…”（多放于句首）1.While he loves his students,he is very strict with them.。
虽然他爱他的学生，可是他对他们很严格。
2.While these experiments are interesting and useful,it is important to remember that they may not always tell us much.(BookIIIp125)
虽然这些实验很有趣也有用，但是很重要的是要记住，这些实验也可能不会告诉你很多。
（3）引起条件状语，意思是“只要”
1.While there is life there is hope.只要生命存在，就有希望。
2.While there is a way there is away.有志者事竟成。