https://reurl.cc/8eEx0j
The CGEL (p710) states that already "characteristically occurs in positive
clauses". But it later notes:
(Still and) already are certainly not wholly excluded from falling within the
scope of a negative, but they do so only under restricted conditions ... .
The Collins Cobuild English Grammar (p262) specifies three of these
conditions with examples:
Note that 'already' cannot normally be used in negative statements, but can
be used in negative if-clauses, negative questions and relative clauses.
Refer certain types of death to the coroner if this has not already been done.
What does it show us that we haven't already felt?
... all peers who did not already belong to the Privy Council.