My best Thai language adventure happened in Bangkok’s largest slum, Klong Toey. I was translating for a Far East Evangelism Team (FEET) who were doing a special Sunday service for the members of a small Baptist church there. After songs, a Youth With A Mission (YWAM) skit, and a prayer, the team leader made way for the pulpit to preach with me by his side.
My friend Bruce Geske was translating for another guy at Thai Lanna Church in Chiang Mai. Instead of saying "we serve a great God" his tone mistake resulted in "God is a very obese woman!" Thankfully, Thai's have a well developed sense of humor.
We were doing fine, sharing a nice devotional about The Sermon On The Mount, when John, describing God’s goodness said, “The grace of God can be compared to riding a horse.” I stopped translating and stood making funny faces at the floor. I knew the words for horse and riding, but I had no idea which tone to use. Great.
After a ten second hesitation I guessed the tones and formed the sentence: “Pra Kun Kong Pra Chao Muan Kii Ma.” The second I finished saying it, the pastor howled with laughter, followed by the entire congregation. 50 Thai’s, half of them falling to the floor with their guts clenched, laughed themselves to tears.
What was so funny?
Instead of using high tone to say horse, I used rising tone, which resulted in dog. And instead of using mid tone for riding I used falling tone, which is a very bad word for poop or excrement.
Instead of saying the grace of God is like riding a horse, I said the grace of God is like dog sh-t! No wonder the pastor laughed so hard. They had a translator in the pulpit who called himself a missionary but looked no more than 12 years old, changing a sacred attribute into profanity.
The Thai language has 44 consonants and 21 basic vowel combinations. It reads from left to right, but there are no spaces between words and any word can read: right to left, left to right, from middle to above the line, from middle to below the line, and from first consonant to last and back to middle to complete the phonogram; Thai will keep you on your toes.
To further complicate matters Thai is a tonal language. One word that sounds identical to the untrained ear, depending on which of the 5 possible tones is used, can mean five completely different things. To know the tones you need to know which of the three consonant classes are used in the word, notice any of the four tone marks present, and then remember if this particular word represents one of the seemingly endless exceptions to the rules.
Take the word Khao as an example. This word can mean: rice, white, mountain, news, enter, and he or she. One word, 6 possible meanings, and the critical part of getting it right is applying the correct tone.
During my studies I consistently called people older than me pii (falling tone), which is Thai for demonic spirit instead of the honorific particle of Pii (rising tone), which is how I was supposed to address someone older than myself respectfully. I didn’t understand the consternation of my elders at the time.
Normal Is Over. 
I hear of a missionary getting up and saying “Sawadi krap, Phom chuu _____, phom me luk sam gon” and everyone started busting up and couldn’t stop. “gon” is the classifier for round objects not children (“kon”) so he just said “hello, My name is ______, I have three testicles”
I liked that one. Of course I’ve never screwed up the language ;).
I think you should go with God’s grace is like dog poop and develop a sermon around that Steve.