Have you not already finished reading this book?
Has Susan not already worked in this company for years?
(1)Are the two sentences correct? My teacher said that “already” can only be used in an affirmative sentence, but I found some information in a grammar book. It says that the word already can be used in an interrogative or negative sentence to mean earlier than the time expected.
E.g. Have you done it already?
(2)Should I abbreviate "has/have and not" to "hasn't/haven't"?
(3)Is it more common to abbreviate them?
(4)What's the difference between the abbreviated form and the unabbreviated form?