Generally speaking, it is best to try to communicate with Thai people in English, because they can probably speak much better English than you can Thai! Also, generally, the Thais you are likely to meet probably have some knowledge of English because they are used to serving tourists.
There are times, however, when a little Thai might be useful or necessary, or interesting and fun. Below are a few phrases which might be helpful. It is not necessary to worry about all the fine distinctions of grammar as Thais will realise you are a guest and are simply trying to do very basic communication.
One can greet Thais with the standard greeting, sawatdi, which means good moring or good evening. You can ask some how they are doing with the phrase, sabaai di mai, which means are you happy?
Everyone should be able to say "yes" or "no". For yes, men say Krap or cup and women say Ka.
These words can also used to say thank you. No is mai.
These words could be used to indicate if you like or don't like something but the phrases phom shobb (I like) and phom mai shobb (I don't like) are more appropriate. Maybe or I don't know is banng-thi or mai roo.
It should be noted that almost all Thai people know the meaning of the English word, "okay!"
To express politeness, say karuna for please. Thank you is expressed khob khun or khob chai.
You're welcome is expressed mai pen rai, which is also used to mean don't worry or don't worry about it.
To apologise (I am sorry), say khaw thod.
It should be noted that almost all Thais know the meaning of the English word "sorry!"
Much of the communication the visitor to Thailand needs is simply the ability to ask questions. Most questions will probably be "where" questions. Where is expressed as thi-nai? It is placed after the thing you want to find.
Connect them together with "you". For example, where is the toilet? is expressed as hong nam you thi-nai? (hong nam is toilet) and where is the bus stop? is expressed as thi chawd-rot pracham-thanng you nai?
If you don't know the the words for items or places such as bus, bus stop or toilet, you can usually use English as many Thais are familiar with these English words.
Visitors to Thailand also need to ask "when" questions a lot. The Thai word for when is meua rai and word for time is wey lar.
The simplest way to communicate is just to ask "wey lar movie" or “train meua rai”.
The clerk will probably grasp what you are trying to get. Be sure you have a note pad for the other person to write on because they will answer you in Thai. Some verbs that might prove helpful here are arrive – ma teuhng, leave - awk, begin – rerm-tonh, and finish – chob.
Another activity customers do which requires the use of questions is shopping. The Thai phrase for "Do you sell?" is mi khaai mai?
Thus, one could ask, "Pepsi mi khaai mai?" If you want to see some more items, you can say, Mi hai dou ik mai?
In shopping, of course, the most important question is "How much does it cost?" which is Thao-rai? If you feel that asked for price is too expensive, then say, Phaeng Pai, which means "that is too expensive".
When shopping, a note pad or calculator should be available since a clerk will probably not be able to tell you prices in English. Most Thais who do business with foreigners on a regular basis, however, have pretty good shopping English so usuallly there will not be serious problems with communication.
Guests in Thailand will almost certainly want to eat out. Always ask for the menu! "Do you have a menu in English?" is Mi menu aharn phasa Angkrit mai? When you want to order, you can say, "Please bring me.." which is "Karuna aow..." or "Can we have..." which is "Khaw...".
At this point, you only need to learn the names of some common Thai foods to complete the phrase. Two common and very "safe" foods to order are fried rice, khao-phad (khao phad kai is fried rice chicken) or fried noodles, Phat thai sai khai. When ready to go, you can ask for the bill, Khid ngoen duai? If you were pleased with the meal, it is appropriate to offer appreciation, A-harn aroi di.
At a hotel, if you will want to ask for a room, the phrase for this is, phom tongkarn hong.
This phrase can be used to ask for specific types of rooms! The phrase, for example one can ask for an air conditioned room, is Phong tongkarn hong mi khreuang prab-akaad.
You will probably want to see the room before you decide to take or not, so ask, Phom khaw dou hong? You can ask the price of a room with the following phrase: Hong ni khid ra-kha thao-rai? (what is the charge for this room?). You can accept the room thus: Phom aow hong ni. When ready to pay and leave, you can say, Phom chah chai bill diao-ni.
If you do not feel well you can tell someone you need to find a doctor Phom mai sabaai. Phom tong phob maw.
You can ask if there is a drugstore of pharmacy nearby, Thaew-ni mi rann khaai-ya mai?You can tell the doctor or pharmacist what is wrong.
You can point to where you feel pain and say, Phom puad thi-ni (I have a pain here.) You can try to be specific: Phom puad lang is "I have back pain", and Phom puad na-ok is "I have chest pain". Phom puad si-sah is "I have a headache" and Phom cheb khaw is "I have a sore throat".
Note: In Thailand most doctors, although not most pharmacists, can speak some English.
At the post office, use this phrase when you tell the clerk you want to mail a letter to an overseas location: Phom tongkarn song chodmaai ni pai... Use this phrase to ask how much postage is needed: Tong pid stamp thao-rai?
It is a good idea to send letters and packages by airmail so tell the clerk, Song thang a-kaad.
It is also a good idea to send overseas letters and parcels registered, so ask, "Long thabian dai-mai?"
Some useful post office vocabulary is as follows: letter – chodmaai, airmail letter – chodmai akaad, post card – praisaniyabat, registered – long-thabian, registered letters – chodmaai long-thabian, postage stamp – duang tra praisaniya-korn, postman – bourut praisani.