query: SELECT first_name FROM Staff EXCEPT SELECT T2.first_name FROM Lessons AS T1 JOIN Staff AS T2 ON T1.staff_id  =  T2.staff_id
question: What-all that first name of that staff ain't give no lesson?
query_toks: SELECT first_name FROM Staff EXCEPT SELECT T2.first_name FROM Lessons AS T1 JOIN Staff AS T2 ON T1.staff_id = T2.staff_id
query_toks_no_value: select first_name from staff except select t2 . first_name from lessons as t1 join staff as t2 on t1 . staff_id = t2 . staff_id
question_toks: What-all that first name of that staff ain't give no lesson?