DON'T EXPECT TO BE UNDERSTOOD.
THE BIGGEST COMMUNICATION ISSUE WITH THAIS WHO SPEAK SOME ENGLISH IS LACK OF COMPREHENSION
When asking a Thai who seems to speak English, a seemingly simple question, I often get answers that are totally wrong. This is not because the person is stupid, it is because the person thought they understood your question, but in reality they didn't, but they don't want to admit that and lose face so they give the best answer they can.
WHY IS THIS SO?
Because what little English they learn in school does not include the everyday language used by English speakers so the words we often use daily, they never learned. Expect to be able to have a very simple conversation like "How are you?" and get an answer like "I'm fine and you?". But do not expect to be able to say "How has your day been going so far?" and get a sensible answer. They will probably think that you think their day has traveled far away and you are crazy.
This one of the biggest reasons, other than getting ripped off by double pricing, that you will need our help when you arrive.