I spend two hours, three days a week, at the Y learning Thai words. I have a large vocabulary stored on my computer - not in my brain.
Tuesday and Thursday mornings I attend more classes here, where the focus is on sentences and tones. If you can't sing, you will never be able to speak Thai. For example, "khaaw plaaw khaaw" means "plain white rice." But each word has a different tone, sort of like singing in the shower, and if you get it wrong, well, just eat what they bring you.
This place is also a travel agency, so if you become fed up with slaughtering the Thai language you can always plan your escape to some other part of the country, where, of course, you will need to speak Thai.
