Here is a list of phrases that are good to know.  These are mostly good for your friends or someone you already know.  However, if you use a phrase or two, you can simply soften the phrase with the proper ending of either ‘ka’ for females or ‘krub’ for males.  You really don’t want to say “Ao mar née” to someone you don’t know without ending it politely. Note the tone marks.

English Phrase Thai Phrase Equivalent
Wait a minute Raw gon Hang on just a second. Raw gon na ka/krub. Can use “diaw na” or “bap neung”.
Go visit Bpai yîam Go visit someone or someplace. Bpai yîam mae (Go visit my mother).
Go see Bpai hăa Same as above. Bpai hăa mae (Go seemy mother).
Give it to me Ao mar née When you want someone to give you something they have in their hands.
Give it back Hâi keun When you hand someone something and then want it handed back.
Take it back Ao keun mar Take it back from me, I don’t want it.
I got it! (Pohm) hâi eng If someone says “turn the lights off when you leave” you can say “hâi eng krub”.
I’ll do it myself Tam eng Don’t worry, I’ll do it myself.
Just X (Past) Pêung X Pêung gin (Just ate) or Pêung bpai (Just left) .
Just X (Present) Cheree cheree Nâng cheree cheree (Just sitting) or Du cheree cheree (Just looking, as in window shopping).
What do you think? Kít yang ngai Say it fast, something like “kid-ngyai”.
I agree Hĕn dûay A great rising tone/falling tone combination.
What happened? Gerd à-rai kêun If you listen long enough, you’ll hear “kêun” quite a bit. It translates to “up”. This might mean something more like “What’s born up?”.
How are you? Bpen yang ngai bâang More like a “Hey, how’s it going?”. Bâang is translated to “some”.
Just sitting around Nâng hăai-jai The answer to “what are you doing?” or “Tam arai yu?”. Just sitting and breathing.
Are you sure? Nâe-jai reuu For real?
I am sure Nâe-jai For real.
A moment ago Mêuagee It happened just a moment ago.
Really Jing jing Used to say “it’s true!” and such.
Let’s go Bpa Shortening of the word “bpai”.
Is that right? Cha ma? Shortening of the question “Châi măi?”.
2 packs Sŏng song To ask for 2 packs of cigarettes.
Times, things and good answers Thai Word(s)
Usually Bpòk-gà-dtì; Tam-má-daa
Maybe Baang tee; àat jà
Probably Kong jà
Might àat jà
Should Kuan jà; Nâa jà
Must Dtông
Sometimes Baang kráng; Baang tee
Somewhere Baang têe
Anywhere Têe năi gor dâi
Nowhere Mâi mii têe
Something Baang yàang; Baang sìng
Anything à-rai gor dâi
Nothing Mâi mii à-rai
Never Mâi koie
Whenever Mêua-rai gor dâi
Anytime Wela gor dâi
No time Mâi mii wela
Always Sà-mĕr
Things Sìng
Before Gon
Until Jon
Since Dtâng dtàe
Later Tee lăng
Depends/Up to (you) Láew dtàe (ter)