For many sentences where I want to say this I can change it to "if/then" as in:

"As long as you keep eating junk food you won't lose weight"

"If you don't stop eating junk food then you won't lose weight".

but what about a sentence like:

"As long as I live in Thailand I will continue learning Thai"

I can change it to:

"If I am still living here then I will continue studying" but that isn't quite the same thing.

ตราบใดที่ ตราบเท่าที่ drab dai tee drab tao tee both mean as long as

I forgot to put that one in my post. I asked a Thai friend about that and she said it is a poetic word that isn't really used in conversation. Unfortunately she couldn't come up with any other way to say it.

กว่าจะ could maybe get the point across...

กว่าจะอยู่ที่นี่ ผมจะเรียนไปเรื่อย

I forgot to put that one in my post. I asked a Thai friend about that and she said it is a poetic word that isn't really used in conversation. Unfortunately she couldn't come up with any other way to say it.

I wouldn’t be so sure about ตราบใดที่ being for poetry.

A search of my computer came up with 7 hits just in the Thai

soap scripts I have on file. As a part of a short example

ตราบใดที่แกยังเป็นน้องฉันอยู่ was in quoted dialogue,

the first and only one I checked.

Also the first time I learned that one was from the babble

of Khun Sonthi a political activist who wasn’t being poetic

either.

เท่าที่ (tao tee) would fit the bill - เท่าที่ผมอยู่เมืองไทย ก็ผมจะคอยเรียนภาษาไทย