Could you recommend a good thai course (monthly or by year) in Pattaya ?

if you are talking about the schools for foreigners to learn thai then I think most of the schools are pretty much the same. Most schools teach using phonetics to start to give you the basics then move into helping you learn and read Thai as well. Whalen school would probably be a bit different set up as you learn the alphabet and reading Thai more at the first and do not focus on phonetics.. So I guess it will be what you prefer

You be better off going to each school, taking a free lesson or two and seeing the approach and also the teacher that is teaching you. Sometimes the teacher and the students make a good class. I been in classes where people wanted to learn and others where they all just sit around and do nothing

If you got the money to go private then you can also shop around each school and take a free lesson to see how the methods of each teacher is and if it is a good match for you.

There better courses out there for serious learners like Payap University Intensive Thai but think that is only limited to Bangkok and Chiang Mai. Not sure if there might be a more legit university type course in Pattaya, I would think not, but perhaps.

Thank you for your answer ! I will check around as you say.