Let's study how to say 12 months in Thai language.

"duean" means "Month" in English and "getsu" in Japanese.
duean mak-ga-raa-kom (January)
duean gum-paa-pan (February)
duean mee-naa-kom (March)
duean may-saa-yon (April)
duean preut-sa-paa-kom (May)
duean mi-tu-naa-yon (June)
duean ga-rak-ga-daa-kom (July)
duean sing-haa-kom (August)
duean gan-yaa-yon (September)
duean dtu-laa-kom (October)
duean preut-sa-ji-gaa-yon (November)
duean tan-waa-kom (December)

***kom=31 days, yon=30 days and pan=28 or 29 days
We can omit "kom, yon and pan" when we speak. The easy way to speak we can speak duean neung till duean sip-song like Japanese language. Be sure you can count 1 to 12 in Thai language.

Let's learn how to say 12 months in Japanese language.
"getsu" means "month", but when we speak 12 months, we have to change "getsu" into "gatsu" as the following.
-ichi gatsu (January)
-ni gatsu (February)
-san gatsu (March)
-shi gatsu (April)
-go gatsu (May)
-roku gatsu (June)
-shichi gatsu (July)
-hachi gatsu (August)
-ku gatsu (September)
-juu gatsu (October)
-juu-ichi gatsu (November)
-juu-ni gatsu (December)