感受一下什么是“嵌入式关系分句”
今天有朋友在饭团上向我提问这样一个问题：
...found record levels of marketing resistance from consumers; a majority reported negative opinions about marketing and advertising and said they avoid products they feel are overmarketed.
they avoid products they feel are overmarketed这句话为什么用了are？意思看得懂，但句子结构怎么分析呢？
我们把这段话的从句部分提取出来：
they avoid products they feel are overmarketed.
这段话其实是由两个从句构成：
They avoid products... 什么样的products呢？that they feel are overmarketed修饰products，这是一个定语从句。
定语从句部分they feel are overmarketed中又含有一个宾语从句, they feel that are overmarketed.
that are overmarketed是products的修饰语，也是they feel的宾语，这种结构被称为“嵌入式关系分句” -- 宾语从句“嵌入”到了定语从句中。《新编高级英语语法》中给出了这样的例句：
She has an adpoted child who she says was an orphan. (她有一个她说曾是孤儿的养子/养女。）
I've got a proposition that I'm sure will interest you. （我有一个提议相信会引起你的兴趣）
注意，they avoid products they feel are overmarketed这句话中的“they feel”和“插入语”差不多，把they feel删掉也不会影响句子结构的完整性。但是要注意它和真正的插入语还是不同的。
那这句话把are去掉，写成they avoid products they feel overmarketed对不对？如果这样写的话从句部分就变成了：
they feel products overmarketed. ❌
feel一般不会这样用。Practical English Usage中说明了feel的用法：
我们可以写成：
they feel products to be overmarketed. (比较正式、少见）✅
they feel that products are overmarketed. （更常见，也是问题中作者的写法）✅
从这一个问题中我们可以至少学到两件事。一是有疑问就主动去解决，自己解决不了可以去问问别人（例如问我啊😄）；二是要注意动词的语法特点，不确定就要多查查字典和工具书。
“学起于思，思源于疑”，如果你有一段时间没有过疑惑、没犯过错误的话，可能你这段时间并没有在学习。当我们有疑惑和犯错误的时候，不要沮丧，反而是要高兴才是，因为这意味着我们有进步了呢。