In Thai, there are 2 ways to say years when referring to someone’s age.

They are ขวบ (kùap) and ปี (bpee). ปี is also the word for year in general.

Do you the difference between the words and know when to use ปี and when to use ขวบ (kùap)?

ปี

As I mentioned earlier, ปี (bpee) is the regular word for year. But when referring to someone’s age in years you use ปี when the person is over 12 years old. For example:

• He is 60 years old.
  เขาอายุหกสิบปี
  kăo aa-yú-hòk-sìp-bpee
  
  
• She will turn 39 years old tomorrow.
  พรุ่งนี้เธอจะอายุสามสิบเก้าปี
  prûng-née ter jà aa-yú săam-sìp-gâo bpee

ขวบ

When talking about the age of a child or someone younger than 12 years old you would use ขวบ (kùap).

For example:

• Right now she is 10 years old.
  ตอนนี้เธออายุสิบขวบ
  dton-née ter aa-yú-sìp-kùap
  
  
• I am 5 years old.
  ฉันอายุห้าขวบ
  chăn aa-yú-hâa-kùap

Summary

I hope this clarifies any confusion you might have had and now know when to use ขวบ vs ปี (kùap and bpee). To summarize use ขวบ when someone is younger than 12 and use ปี when someone is older than 12 years old.