The Thai people that you may encounter in hotels in tourist areas will have more advanced English skills.
I believe that English is one of the main second languages in Thailand and as such, you will also find that many business people, if their businesses require contact with international clients, will also have some English skills as well.
When you start to travel outside of Bangkok and other areas like Phuket, Samui etc. you will find that there are many millions of Thai people with little or no English at all.
Once you yourself begin to learn Thai, you will find that the whole place will 'open up' to you. Even in the parts of the country where English is more widespread, to be able to speak to and understand people in the Thai language is, I believe, a very important, if not essential skill to acquire.
Thai schools all have English as part of the curriculum, but it would not be true to say that most Thai people can speak English at a level that is of any use to them. For one thing, they don't get to use it much in everyday life. Also there are a number of other Thai languages apart from what is referred to as 'Central Thai'
In my country, the UK, we have language programmes in schools, mainly French, German and a few other European languages, however, it would definitely not be true to say that English people can speak French!
for the Thai language
