I used to speak quite a bit of thai going back thirty years.
I have been speaking khmer for three years and i find it much more diffficult than thai.
Last week I was in saigon and I bought the lonely planet phrase book.Vietnamese does not seem difficult thanks to the roman script.
People say that vietnamese and thai are difficult due to the tones,I find the tones far less onerous than grammar problems.
I would like to go to issaan where khmer is spoken,anyone know about the form of khmer language there?