固然的英文：
admittedly
true
no doubt

参考例句：

He is indeed young, but he is competent.
他固然年轻，但他很称职。

His prudence is parallel to his zeal
他固然谨慎，也同样热心。

"Birth is much, But Breeding is more"
出身固然重要,教养更且重要

Staying just as you are may not help you advance spiritually, but it certainly is comfortable in its familiarity.
墨守成规，不思进取固然安逸，却无益于心灵的成长。

I, indeed, talked comparatively little, but I heard him talk with relish.
我固然谈得比较少，可是我兴致勃勃地听他谈。

Your suggestions are good indeed,but they don't quite dovetail into the rest of the plan.
你的建议固然很好，但跟计划的其余部分不很协调。

True, life's journey is full of frustrations, But I hope you will march on steadily, and make still greater progress.
人生的旅程固然坎坷不平，祝愿你脚踏实地，百尺竿头，更进一步。

True, life's journey is full of frustrations,but I hope you will march on steadily, and make still greater progress.
人生的旅程固然坎坷不平，祝愿你脚踏实地，百尺竿头，更进一步。

Yet the rate of change, though exhilarating, was disturbing
然而变化太快了，固然令人兴奋，也使人不安。

"Love sought is good, But given unsought is better"
追求而得的爱情固然美好,但不经追求而得的爱情更为美好

admittedly是什么意思：
adv. 公认地，无可否认地

This choice of terminology is admittedly a bit awkward.
大家公认术语的这种选法有些不合理。

The subject of racism is admittedly too complex for facile summarization.
无可否认，种族主义这个话题太过复杂，不可能一言蔽之。

Admittedly, these misunderstandings have done little harm outside the historicist workshop.
当然，这些误解在历史决定论的研讨会之外是没有什么害处的。

true是什么意思：
adj. 合乎事实的；确实的；真正的；忠实的
adv. 真实地；不偏不斜地
n. 真，真实

That was a true victory.
这是个真正的胜利。

In a sense, it is true.
在某种意义上说，这是正确的。

True power and true politeness are above vanity.——Voltaire
真正有权力和真正有礼貌的，都不虚荣。——伏尔泰

doubt是什么意思：
n. 怀疑；疑问；疑惑
v. 对…无把握；怀疑；不信；拿不准；恐怕

benefit of the doubt
裁判员对可疑情况无把握时不对有关运动员作不利判定

They were beset by doubts and fears .
他们被疑虑和恐惧所困扰。

Being such as to debar questioning or doubts.
无异议的如此以至使质疑或怀疑都没有必要的。