okay, if it goes as you said, "last" and "most" are to be there in that sentence in order to modify adjective "important", then I would think that sentence is incorrect! just as her own original sentence:
The last and the most important is pronunciation
So what is the point of making corrections here?
I would agree with Mr.Nguyen that sentence would better be : You're right that the word "important" is an adjective.
Clear now?
and for the "mistook" mistake, if it isn't "mistook", then it is "mistake", isn't?
Truthfully, I don't got the use of these two. I thought the sentence is in the past tense; therefore, every word should be in past tense,too
There are many ways to correct this mistake while still keep the meaning the same. English is varies as well as vietnamese is.
p/s: it isn't wise to wake 2 tigers at the same time. Instead, make they kill each other or kill each silently lolz