网友句子中的 actually 为句子副词，用于修饰全句。

actually 到底是修饰哪个成分，取决于它表示什么用法：

1. 用作句子副词：若是用于补充新的信息、说明个人观点或开始新的对话等，属于句子副词，起评注性状语用作，此时是修饰整修句子，而非某个具体的成分——这样用的actually虽然被放在句子中间，其实也可以移到句首：

The school is actually a listed building. 实际上，这所学校是一处文物保护建筑。

Alcohol, thought to be a stimulant, is actually a depressant. 通常认为酒精是兴奋剂，实际上它是镇静剂。

She likes him very much. He is actually is her boyfriend. 她很喜欢他，实际上，他是她的男朋友。

Superficially, the twin sisters are very alike, but there are actually a lot of differences between them. 乍一看这对双胞胎姐妹很像，但实际上他们有很多不同点。

2. 用作强调副词：若是用于表示强调，即强调某种真实情况，属于强调副词，此时它是强调哪个成分，就可分析为修饰哪个成分：

There is actually one thing you can do to help. 你确实可以帮忙做一件事情。

Can it be that these people are actually sincere after all? 这些人究竟是不是真的诚实？

Much to my surprise, the restaurant was actually very nice. 令我吃惊的是，这个餐厅实际上非常好。

It’s too early to say whether this virus is actually the cause of the disease. 说这种病毒确实能引起该病还为时过早。