I told them how tall the tree was.

网友的句子，两种理解都可以。

表示感叹：

I told them the tree was really very tall.

表示疑问：

I told them the extent to which the tree was tall.

I told them how tall the tree was.

备注:以上网友这个句子有以下2种理解。

【1】 I told them how tall the tree was.【感叹分句】

参考译文：他们告诉我这棵树是如此的高。

备注:以上理解为how引导“名词性感叹分句”中的“直接宾语从句。”

 【2】 I told them how tall the tree was.【疑问分句】

参考译文：他们告诉我这棵树有多高。

备注:以上理解为how引导“名词性疑问分句”中的“直接宾语从句。”