He rang off before I could explain.

我还没来得及解释他就挂了。

《牛津词典》

She ran away before I could explain to her.

我还没来得及向她解释她就跑了。

youdao

If he were here I could explain to him myself.

要是他在这里，我就可以亲自向他解释了。

youdao

So, for example, there's a magician-- The question is not, could I explain to you how the seance manages to do the amazing things that it does?

比如说,有一个魔术师,问题不在于,我能否给你解释通灵任何,做到这些惊人事情的

耶鲁公开课 - 死亡课程节选

You could use "I've already" pattern to explain why you don't want to go to Japan again.

你可以用“I've already”句型来解释你为什么不想再去日本了。

I've already 课堂 - SpeakingMax英语口语达人

Instead, I am an economist and business person and I see an economic mountain looming in front of the U.S. I only wish I could explain why Washington insists on flying straight into the mountain rather than pulling up.

FORBES: Goodbye Recovery, Hello Recession

" His sons were full of questions "but I could only explain certain parts.

CNN: Just Fooling Around

Well maybe if I could just explain very briefly.

BBC: Irish abortion referendum: Your questions