$ sed --version
GNU sed version 4.1.4
Copyright (C) 2003 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE,
to the extent permitted by law.

$ head file1 sed1
==> file1 <==
11111'222?'22'33?'333'44444'55555'

==> sed1 <==
s/\([^?]\)'/\1'\n/g

$ sed -f sed1 file1
11111'
222?'22'
33?'333'
44444'
55555'