Database schema:
CREATE TABLE conference (
  Conference_ID NUMBER PRIMARY KEY,
  Conference_Name TEXT,
  Year NUMBER,
  Location TEXT
);
CREATE TABLE institution (
  Institution_ID NUMBER PRIMARY KEY,
  Institution_Name TEXT,
  Location TEXT,
  Founded NUMBER
);
CREATE TABLE staff (
  staff_ID NUMBER PRIMARY KEY,
  name TEXT,
  Age NUMBER,
  Nationality TEXT,
  Institution_ID NUMBER,
  FOREIGN KEY (Institution_ID) REFERENCES institution(Institution_ID)
);
CREATE TABLE conference_participation (
  Conference_ID NUMBER,
  staff_ID NUMBER PRIMARY KEY,
  role TEXT,
  FOREIGN KEY (Conference_ID) REFERENCES conference(Conference_ID),
  FOREIGN KEY (staff_ID) REFERENCES staff(staff_ID)
);

Question: What are the names and nationalities of the people who did not participate in any ACL conferences?
SQL: SELECT name ,  nationality FROM staff WHERE staff_id NOT IN (SELECT T2.staff_id FROM Conference AS T1 JOIN Conference_participation AS T2 ON T1.conference_id  =  T2.conference_id WHERE T1.Conference_Name  =  "ACL")

Question: What are the different conference names?
SQL: SELECT DISTINCT conference_name FROM conference

Question: What are the names of all the conferences that has staff from Canada attending?
SQL: SELECT T1.conference_name FROM conference AS T1 JOIN conference_participation AS T2 ON T1.conference_id = T2.conference_id JOIN staff AS T3 ON T2.staff_id  =  T3.staff_id WHERE T3.nationality  =  "Canada"

Question: show all years and the number of conferences in each year.
SQL: SELECT YEAR ,  count(*) FROM conference GROUP BY YEAR

Question: Show all staff names who attend a conference in 2003 or 2004.
SQL: SELECT DISTINCT T1.name FROM staff AS T1 JOIN conference_participation AS T2 JOIN Conference AS T3 ON T1.staff_id  =  T2.staff_id AND T2.conference_id  =  T3.conference_id WHERE T3.year  =  2003 OR T3.year  =  2004

Question: Show institution name which there is no staff in our record.
SQL: SELECT institution_name FROM institution WHERE institution_id NOT IN (SELECT institution_id FROM staff)

Question: What are the maximum and minimum ages for all staff?
SQL: SELECT max(age) ,  min(age) FROM staff

Question: For each conference id, what are their names, year, and number of participants?
SQL: SELECT T1.conference_name ,  T1.year ,  count(*) FROM Conference AS T1 JOIN Conference_participation AS T2 ON T1.conference_id  =  T2.conference_id GROUP BY T2.conference_id

Question: How many institutions were founded between 1850 and 1900?
SQL: SELECT count(*) FROM institution WHERE founded BETWEEN 1850 AND 1900

Question: List all conference name, year, and location.
SQL: SELECT conference_name ,  YEAR ,  LOCATION FROM conference

Question: What year had the fewest conferences?
SQL: SELECT YEAR FROM conference GROUP BY YEAR ORDER BY count(*) LIMIT 1

Question: Show all staff name who are above the average age.
SQL: SELECT name FROM staff WHERE age  >  (SELECT avg(age) FROM staff)

Question: Show all conference names which the staff from Canada attends.
SQL: SELECT T1.conference_name FROM conference AS T1 JOIN conference_participation AS T2 ON T1.conference_id = T2.conference_id JOIN staff AS T3 ON T2.staff_id  =  T3.staff_id WHERE T3.nationality  =  "Canada"

Question: What are the staff names who participated in conferences between 2003 or 2004?
SQL: SELECT DISTINCT T1.name FROM staff AS T1 JOIN conference_participation AS T2 JOIN Conference AS T3 ON T1.staff_id  =  T2.staff_id AND T2.conference_id  =  T3.conference_id WHERE T3.year  =  2003 OR T3.year  =  2004

Question: List all distinct conference names.
SQL: SELECT DISTINCT conference_name FROM conference

Question: Find the name and nationality of the people who did not participate in any ACL conference.
SQL: SELECT name ,  nationality FROM staff WHERE staff_id NOT IN (SELECT T2.staff_id FROM Conference AS T1 JOIN Conference_participation AS T2 ON T1.conference_id  =  T2.conference_id WHERE T1.Conference_Name  =  "ACL")

Question: What are the names of the conferences that have the top 2 most people attending?
SQL: SELECT T1.conference_name FROM Conference AS T1 JOIN Conference_participation AS T2 ON T1.conference_id  =  T2.conference_id GROUP BY T2.conference_id ORDER BY count(*) DESC LIMIT 2

Question: Show the conference name and year and the number of participants for each conference.
SQL: SELECT T1.conference_name ,  T1.year ,  count(*) FROM Conference AS T1 JOIN Conference_participation AS T2 ON T1.conference_id  =  T2.conference_id GROUP BY T2.conference_id

Question: What are the names of everbody who has participated in both the ACL and NACCL conferences?
SQL: SELECT T1.name FROM staff AS T1 JOIN conference_participation AS T2 JOIN Conference AS T3 ON T1.staff_id  =  T2.staff_id AND T2.conference_id  =  T3.conference_id WHERE T3.Conference_name  =  'ACL' INTERSECT SELECT T1.name FROM staff AS T1 JOIN conference_participation AS T2 JOIN conference AS T3 ON T1.staff_id  =  T2.staff_id AND T2.conference_id  =  T3.conference_id WHERE T3.Conference_name  =  'Naccl'

Question: Show all conference names and the number of times each conference has.
SQL: SELECT conference_name ,  count(*) FROM conference GROUP BY conference_name

Question: How many conferences occur every year?
SQL: SELECT YEAR ,  count(*) FROM conference GROUP BY YEAR

Question: which year has least number of conferences?
SQL: SELECT YEAR FROM conference GROUP BY YEAR ORDER BY count(*) LIMIT 1

Question: Show all locations where at least two conferences are located.
SQL: SELECT LOCATION FROM conference GROUP BY LOCATION HAVING count(*)  >=  2

Question: What are the names and locations of the most recently-founded institution?
SQL: SELECT institution_name ,  LOCATION FROM institution ORDER BY founded DESC LIMIT 1

Question: Show the institution name, location and founded year of all institutions.
SQL: SELECT institution_name ,  LOCATION ,  founded FROM institution

Question: How many institution are founded between 1850 and 1900?
SQL: SELECT count(*) FROM institution WHERE founded BETWEEN 1850 AND 1900

Question: Find the name and location of the universities that did not have any staff participated in any conference in 2004.
SQL: SELECT T1.Institution_Name ,  T1.location FROM institution AS T1 JOIN staff AS T2 ON T1.institution_id  =  T2.institution_id WHERE T2.staff_id NOT IN (SELECT T4.staff_id FROM Conference AS T3 JOIN Conference_participation AS T4 ON T3.conference_id  =  T4.conference_id WHERE T3.year  =  2004)

Question: What is the name of the institution with no staff in the records?
SQL: SELECT institution_name FROM institution WHERE institution_id NOT IN (SELECT institution_id FROM staff)

Question: Show all names who have been in both ACL and Naccl.
SQL: SELECT T1.name FROM staff AS T1 JOIN conference_participation AS T2 JOIN Conference AS T3 ON T1.staff_id  =  T2.staff_id AND T2.conference_id  =  T3.conference_id WHERE T3.Conference_name  =  'ACL' INTERSECT SELECT T1.name FROM staff AS T1 JOIN conference_participation AS T2 JOIN conference AS T3 ON T1.staff_id  =  T2.staff_id AND T2.conference_id  =  T3.conference_id WHERE T3.Conference_name  =  'Naccl'

Question: What are all locations that have hosted at least two conferences?
SQL: SELECT LOCATION FROM conference GROUP BY LOCATION HAVING count(*)  >=  2

Question: For each conference name, how many times has it occurred?
SQL: SELECT conference_name ,  count(*) FROM conference GROUP BY conference_name

Question: How many conferences are there?
SQL: SELECT count(*) FROM conference

Question: What is the maximum and minimum age of all staff from the United States?
SQL: SELECT max(age) ,  min(age) FROM staff

Question: Find the name of the conferences that have the top 2 most number of attendants.
SQL: SELECT T1.conference_name FROM Conference AS T1 JOIN Conference_participation AS T2 ON T1.conference_id  =  T2.conference_id GROUP BY T2.conference_id ORDER BY count(*) DESC LIMIT 2