Pronouns in Thai:

"I"

ฉัน (Chan) : normally use but a bit girlish

ดิฉัน (di-chan): only for Female

เรา (rao): normal use..but so childlish! ^ ^U

ผม (Pom): only for male

กระผม(kra-pom): only for male...the full word of Pom

เค้า/เขา (khao): cute word...always use for your friend or your lover

กู (gu): unpolite word, mostly use in frends group but...don't try to use it.

ตู (tu): this word changed from ...gu

ข้า(kah): old word(you can hear from Chinese Action movies that dupped in Thai..they use it)

อาตมา (aat tama): only for the monk ^ ^U...if you are not ..don't try to use!!!

"you"

เธอ (ther): normally use but a bit girlish

คุณ (kun): normally use...better use this word ^ ^

นาย (Nai) : use for calling the male"you"

ตัว (tua)/ตัวเอง (tua eng) : use for your darling...
if you want to make cute ...say"tuaaaaaaa...(longer)" or "tua eeeeeeengggg" >_<

มึง (Mueng): unpolite..use in group of friend...don't try

เจ้า (Jao): old word

ท่าน (than): very polite ^^U ..too polite to use in everyday life.

โยม (Yom) :only for monk use..for calling normal persons.

"we"

put the word พวก "puag" in front of the pronoun I

example: พวกเรา "puag rao" (mostly use!!!)
but this word you also can use it shorter as...Rao

"you" (pural)

put พวก "puag" in front of the pronoun you

example: พวกคุณ "puag kun"

"he/she/it"

เธอ (ther): she

หล่อน (Lon) : she

เขา (khao): he...but can use for She too

มัน (man): it ..but unpolite use for he and she

"they"

put the word พวก "puag" in front of the pronoun he, she, it

example: พวกเขา"puag khao"

*****Plusssss... some Thai people ..use their names in stead of the pronoun "I"
like ..if your name is Fer...when you speak you can use your name...

example: เฟอร์ คิดว่ามันสวยดี นะครับ (Fer kid wa man suay dee nakrab)
means ..I think that it's beautiful
( คิด kid = to think, ว่า wa= that, มันman= it,สวยsuay= beautiful, ดีdee=good)
..this ..most use in girl.....the man can use too

(from http://rabbiscuit.livejournal.com/)