Thai is a tone language of Sino-Tibetan origin. This means that differences in tone make differences in meaning. The Thai language has five tones, and if you mispronounce you do not simply say an incorrect word, you say another word entirely! Many Thais, however, (not all, of course!) speak some English and at least in the tourist areas of Thailand, like Bangkok, Phuket, or Koh Samui you can manage easily even without knowing Thai (in the more remote areas, like the Northeast, or the South, you might run into problems.) It is also always a good idea to ask the concierge of your hotel or somebody else to write down the names of your destinations in Thai script, and to take a business card of your hotel, and a good bilingual map with you.
There are various systems of transliteration, especially for Thai consonants. In this guide, "Th" means that the sound is a soft "t", and "ph" means that the sound is a soft "p" (not "f").
When traveling in Thailand and having to make one's own arrangements with regard to transport, food and accommodation it will usually be possible to find someone who speaks at least some English. It is extremely rare to encounter a Thai who speaks any non Asian language except English. Obviously for a guest house, hotel, restaurant or tour company it is advantageous to have English speaking employees as travelers gravitate towards any establishment that is going to make life easier. However for the traveler who has acquired even a very basic vocabulary there are many advantages. Everything from hotel rooms to souvenirs can be obtained at a lower cost. This is not only because it will be assumed that someone speaking Thai ( even if rather badly ) is familiar with prices but also because it frees the visitor from having to rely on the popular places to stay , shop and eat. Most important of all it shows an interest in and respect for the country and its people. The modern Thai language is thought to be derived from the Mon and Khmer dialects of what is now Burma and Cambodia with many words taken from Indian Sanskrit and Pali, the latter still used by Buddhist monks. In common with Chinese and other Asian languages it is tone sensitive. For Westerners the latter is the most difficult aspect of the language to master. The same word can have up to five different meanings depending on the tone used when pronouncing it - flat, high, low, falling or rising. That's the bad news but it's probably no worse than English speakers inflicting pronunciations such as 'rough', 'though', 'through', 'cough' and 'bough' on the rest of the world. The good news is that Thai has no genders, articles, plurals or irregular verbs. Despite what well meaning guide and phrase books tell you it is far more important for a short term visitor to acquire a working vocabulary than worry overmuch about the use of tones. You are only going to be using simple phrases and in most cases you will be understood by the context. The Thai alphabet employs a non-Roman script consisting of 44 consonants and 24 vowels. Writing proceeds from left to MainWindow and there are no spaces between the words. For the short term visitor there is no need for any knowledge of Thai script. All railway stations, town signs, main streets, most information in public buildings and transport timetables are displayed in Thai and English. The better guide books include Thai script on maps, places of interest and in the food and drink section to enable the reader to point to the appropriate word if all else fails.