Question

Many teenagers are surprised to learn English.

Many teenagers are surprised to learn English.这个句子这样划分句子成分？它是主谓宾结构还是主系表结构？还是其它？具体怎么样划分？
Many teenagers are surprised to learn that when you exercise，your body produces
some chemicals that make you feel peaceful and relaxed and increase your ability to
concentrate when you study .原句是这样，怎么样分析呢？

Answer 1

that when you exercise，your body produces
some chemicals that make you feel peaceful and relaxed and increase your ability to
concentrate when you study
1. 它是主系表结构。

2. 具体分析如下：
主语：Many teenagers
系动词：are
表语：surprised
(原因)状语：to learn that when you exercise，your body produces
some chemicals that make you feel peaceful and relaxed and increase your ability to concentrate when you study.
注：此句用不定式做原因状语，再如：
I'm sorry to hear the news.

3. 做原因状语的不定式中的learn后面是一个以that作为引导词的宾语从句。
该宾语从句结构分析如下：
when you exercise为宾语从句中的时间状语从句（其中的you和exercise分别为时间状语从句的主语和谓语）；
your body为主语；
produces为谓语；
some chemicals为宾语；
其后的that make you feel peaceful and relaxed and increase your ability to concentrate when you study为定语从句，修饰chemcals做定语。

4. 该定语从句分析如下：
1）that即是定语从句的关系代词/引导词，又在定语从句中充当主语，相当于先行词chemicals；
2）make为谓语；
3）you为宾语；
4）feel peaceful and relaxed以及increase your ability to concentrate为用and并列的两个宾语补足语；
其中to concentrate为不定式做后置定语，修饰ability；
5）when you study为时间状语从句，其中you和study为主语/谓语。

Answer 2

主语 many teenager
are surprised 是谓语，相当一个被动结构
to learn English 状语

不过这个句子虽对，内容却不知所云

许多青少年学英语很吃惊？不明白

Answer 3

为什么这些事实是 surprised to learn 呢？
好奇怪哦 我觉得这些事情是很自然 一点都不 surprising
可能我不是 teenager了吧

纯属八卦

Answer 4

主系表结构
Many teenagers 是主语are 是系动词surprised 表语to learn English状语.