file.txt to the staff group:chgrp staff file.txt
/home/user1/docs/ and its subdirectories to the users group:chgrp -R users /home/user1/docs/
/home/user1/docs/ and its subdirectories to the users group, and display the process:chgrp -vR users /home/user1/docs/
file.txt to the same group as the reference file file2.txt:chgrp --reference=file2.txt file.txt
link itself to the staff group:chgrp -h staff link