Just as a reference point the Thai language course at the Defense Language Institute in Monterry, CA is 48 weeks.

The Mormon guys seem to learn quickly, I after 30 years could not make an order at MacDonalds, they kindly helped me out.

 

They must be pretty good to be able to convince anyone of their absurd beliefs..if they do.

I find that hard to believe. Are you American with 'they should speak English' attitude ? Living in a country for 3 decades and not being able to order food is disgusting.

If you end up with a woman who is open to speaking Thai with you (or who prefers it or can't speak English that well) you can learn pretty quickly out of necessity. Try having an argument (sorry, all couples argue at some point) without vocabulary, etc. We used to crack up after fights and rehash the vocab we had learned in the process. I would say that after about a year here I was ok to do basic things, but then living together abroad it got better. Coming back here to live more permanently really did a lot for my speaking skills. I would say it depends a lot on how much you interact with Thais. Some foreigners here just don't interact with Thai people much (honestly), but if you talk to people in shops and restaurants, you will get a lot better. I would say I speak Thai about 70% of the time here, so it has improved greatly.

Reading and writing are another matter, but, as most people said, it is mostly a question of how dedicated you are. The script isn't as crazy as it first seems, but you do need to put in the time on your own.

Will it open doors? Yes and no. I mean, to really open doors professionally, you would have to get to a pretty high level, and most people have other, more lucrative ways of earning a living. Speaking, though, opens up tons of doors in Thailand, as most people won't be able to really talk to you. You will see a completely different side of the place when the locals see that you know the lingo to a certain extent (ie., have a relatively fluid conversation with them). You would be amazed at how people change when they speak with someone who is perceived as "getting it," and not all negative stuff, either...just more information. And it is nice to be able to order food on your own from a Thai menu. Independence.

I started with Lao as my wife is from Isaan and found it easier than Thai (about 1 year). My Thai is passable but the weird thing is I learned to read and write Thai and have found myself writing a word or phrase to a person to get my point across. Good luck it is hard but not impossible.

I've been here for three decades and now I'm fluent in Thai. This came from necessity and I think it's a bit like computers, you only learn enough to be able to do what you want. If you're serious about learning Thai then get lots of Thai friends and hang out with them. Listen to their pronounciation and try to mimic it. Don't worry too much about tones, that will come later. Good luck.

Oh and I forgot another thing,

being able to speak Thai well shows me that most of what foreigners perceive about Thais is totally wrong. If you can't get the language then you really miss something.

The Mormon guys seem to learn quickly, I after 30 years could not make an order at MacDonalds, they kindly helped me out.

They must be pretty good to be able to convince anyone of their absurd beliefs..if they do.

I find that hard to believe. Are you American with 'they should speak English' attitude ? Living in a country for 3 decades and not being able to order food is disgusting.

The Mormons got to school in the US so when they arrive, they can speak reasonable Thai. I mean think about it, you're not going to be able to "convert" anyone if you can't speak the language!