Is the sentence right or wrong?
Mary should study more harder, or she'll fail her exam.
We use the word "than" to compare two objects by one property.
The new model is better than the old one.
The USA is bigger than Mexico.
(Not) as...as means that the objects are (not) the same compared by a certain property.
The second season of the series is as popular as the first one.
My score is not as good as yours.