Question

这是什么从句啊？

Although I hadn’t planned it this way, I discovered that a patriotic tone ran through the talks I gave that afternoon.

Answer 1

这句话里有好几个从句, Although I hadn't planned it this way （虽然我没有这样计划。）是一个让步状语从句。 that a patriotic tone ran through the talks 是动词谓语discovered的宾语从句， I gave that afternoon是一个定语从句，关系代词which/that 由于做 gave的宾语, 所以省去了。

Answer 2

Although I hadn’t planed it this way, I discovered that a patriotictoner ran through the talks I gave that afternoon.
意思是：
尽管我并没有这样计划，但我发现那天下午我的演讲中始终贯穿着一个爱国主义者的情愫。
that 引导宾语从句。

Answer 3

这是宾语从句 discover是动词 ,所以这是宾语从句