No habla English in Thailand
I am sure you seen these men lurking around Nana plaza, Khosan road, Walking street and my encounter outside Wow fitness of all places.
They have a typical British accent and they are walking as they drunk (because they are).
When they spot you as a fellow foreigner that might speak English your answer should be.
“No Habla Englise†or something even fancier in your local language but it is difficult to remember when someone asks you.
If you stop and chit chats with this scum of the earth person you will find your pocket a bit lighter in the end of the conversation. He will not budge before he can talk you into giving him a few THB for a beer or something. If he spots a week or scared person he will try to push you into giving you money even if he would never do anything to risk his staying in Thailand.
I saw one of these guys in Nana Plaza around 03.00 in the morning walking around and he had maybe a few thousand in his hand but still pestering people about more money.
What ever you do never give them anything it will only encourage them to continue pestering people.