100%: always (luôn luôn)
80%: usually (thường xuyên)
60%: often (thường -)
40% - 50%: sometimes (thỉnh thoảng)
20%: occasionally (đôi khi)
0%: never (không bao giờ)
-----→
1. always
2. never
3. Sometimes
4. usually
5. occasionally
6. often
7. occasionally
8. always
9. usually
10. occasionally
11. never
12. Sometimes - usually