“I” CHAN~ (ฉัน) but often pronounced as CHAN’ “I” This is a word used by both males and females (used more by females) when speaking to intimates, friends, servants or children. You should not use it when speaking to people who are superior to you in rank or social status but it is alright amongst friends if you know them well. From the above it follows that if you use Chan’ you will not normally use the “polite” words Ka` or Krap’ at the end of the sentence.
POM~ (ผม) “I” – polite & formal This has the same meaning as Chan’ but is a more “polite” word and is generally used when talking with equals or superiors. This word can only be used by males.
DI` CHAN~(ดิฉัน) but often pronounced as DI` CHAN’ “I” – formal This is the female counterpart of POM and is used in the same circumstances. It is often abbreviated to CHAN’. This word can only be used by females.
KAA^ PA’ JAAO^ (ข้าพเจ้า) “I”- very formal This is a very formal word which may be used by either males or females but is seldom met with except in writing. You will mostly come across it in official documents.
NUU~ (หนู) “Mouse” “I” [Little girl, someone is ] This is often used as a pet name when talking to or about small children or girl friends and corresponds roughly to “little one” as used in English in similar circumstances. Can also be used to waitresses and young servants/juniors/subordinates.
GUU (กู) “I” – impolite This is a rather insulting word which you should never use. It is mentioned here because a Thai can and often does use it to a really intimate friend as a very informal and friendly word.
“You” KHUN/KUN (คุณ) “You” – polite & formal This corresponds to POM~ and DI`-CHAN’ and can be used by either males or females. It is generally used amongst intimates and is a good “polite” word to use to superiors. It is the pronoun most commonly heard in any conversation can be used in either the 2nd. or 3rd. person. As it indicates considerable personal respect, you should not use it to inferiors such as servants or taxi drivers.
TAAN^ (ท่าน) “You” – very respectful & formal This word can be used as a 2nd. or 3rd. person pronoun by either males or females. Actually it is a “polite” word and would be used in conversation by a Thai only when speaking to someone of high rank. In the written language however it is the ordinary word to use for “you”. It shows respect for rank rather than personal respect.
GAE (แก) “You”, “He”, “She”, “They”. This is a 2nd. or 3rd. person pronoun. Used as a 2nd. person pronoun it sounds rather rough and you had better avoid it but you can use it as a 3rd. person pronoun when referring to servants or people of inferior status. A Thai will sometimes use it as a 3rd. person pronoun referring to his friends.
MUENG (มึง) “You” This is another very low word which you should never use although you will sometimes hear Thai people use it to very intimate friends.
TUR (เธอ) “You” This is a very familiar form of address used mainly by women talking to each other, a man talking to his wife or girl friend or when talking to small children. It is also used a 3rd. person pronoun under the same conditions.
RAO (เรา) “We” This can be used in all cases for “we” but sometimes “RAO” also can be used as “I” when talking to equals/friends
PUAK^ RAO (พวกเรา) “We” This is a variation of the above which you may come across in reading and means “Our group” or “Our sort of people”.
KAO~ but often pronouced as KAO’ (เขา) “He”, “She” (“They”) This is the 3rd. person pronoun singular or plural and may be used by either sex referring to anyone. Just as in English however it is more polite to refer to people as NAI or KUN “Mr.” or KUN “Mrs.” or “Miss” rather than just KAO’ “He”, “She” etc.
PUAK^ KAO~ but often pronouced as PUAK^ KAO’ “They” which sometimes can be shorten as “Kao'” and that makes it the same as KAO’ for HE/SHE. IT
MAN (มัน) “It” This is sometimes used for animals and things and for the
impersonal “it” in such sentences as “if you like this, it will be a good thing”. You should not try to use it until you get more familiar with the language. Sometimes used to call the third person too in an impolite/very casual manner.
Source: http://www.learningthai.com/index.php?option=com_content&task=view&id=832&Itemid=77
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