Thailand’s a newly industrialized country which is heavily export-dependent with more than two thirds of GDP (agricultural, textiles, rubber, automobiles, jewelry, computers/electronic appliances etc.)
Thailand is one of the major destinations in the world.
Our official language is Thai. English is a mandatory school subject, but the number of fluent speakers remains very low, especially outside the cities.
Many Thais have a basic grasp of English, they can speak and understand English, especially in Bangkok and the major tourist areas.
People in the travel industry speak at least enough English to communicate and many are relatively fluent; some also speak one or more other languages, such as Chinese, Japanese, German, etc.
The Thai language itself is challenging to master, but Thai people are happy to help foreigners learn a few words to help them get around. However, English is typically the common currency for cross-cultural conversation as Thailand hosts visitors from around the world.
Even if you don't understand Thai, you can still certainly enjoy traveling in Thailand. But if you know a few everyday Thai phrases then it will make your trip even more memorable. A few words make a big difference.