我非常理解他点头是什么意思。

I understood exactly what the nod meant.

youdao

我非常理解他学习英语方面的困难，但却爱莫能助。

I appreciated his problem in learning English very much, but I don't think I can help him.

youdao

我非常理解他的悲伤，甚至也明白他为什么把心绘成黑色的原因。

I could even understand why he had made his heart a dark color.

youdao