Does his speech get better?

If I remember correctly about the stepmother and stepsister thing, in ancient china, the official wife is the only wife of the head of the household that holds authority and any other women that married into the house is considered as concubine and hence, they are just wives in name only but without any power. In the novel the blonde hair guy actually did explain a bit about mc household and mc retaliate the stepmom and sister by saying that they're just concubine and the daughter of a concubine (illegitimate?) that wasn't even married into the house yet and still they dare to assume that he, who was born the legitimate son from the main wife, is of a higher position than them, has to sit in the same car as them aka usually concubines and the subsequent children are all "illegitimate" status so they usually have to ride another carriage from the main house.

I think I kinda like this scene in the novel tbh. The mc was totally so spiteful lolol I love it.

Regarding his speech, iirc, he was reading the history book or smth and he claimed that he lost his memory and he learn how to talk like that from reading the history book or smth smth but don't hold me on that

It is because, his father was the same in the past life. With the step mother and all. So he just assumed it will be the same since his mother is already dead. He will regain back the main person's memories and the speech is how they speak in the past life. And he just says what is right without any filter. He is savage like that

This manhua was from a novel with the same title, they cut quite a lot of scenes for 1 manhua chapter. If I remember correctly, there‘s supposed to be a caretaker who showed song xiao books about ancient china (since he kept talking in ancient way) and the family thought his change of attitude was because of these books‘ influence. The novel was much more detailed than the manhua (though it’s chinese danmei so sometimes something doesn’t make sense and nobody’s questioning) (づ￣ ³￣)づ