It’s also dangerous.
Let’s take the case of the Thai words “mai” and “mai.” They are two entirely different words, depending on your inflection. Raise the inflection as you speak, and it means “no.” Lower it as you speak, and you are saying “new.”
Of course, the Thai language has it’s own characters, which look nothing like the English alphabet. So, you are relying on the transcription of Thai vocal sounds into an English representation. This can be problematic.
Let’s look at another example…
Jen and I do not eat meat. When we first arrived in Thailand, we had read that the Thai word for vegetarian is “jair,” which is pronounced along the lines of “jay.” We later learned that the word we were attempting to say more literally means “vegetable,” not “vegetarian.”
There is a similar-sounding Thai word, also pronounced along the lines of “jay,” but with a slightly different inflection. That is the word for “understand.”
All this perhaps explains the funny looks we received when we kept trying variations of inflection for the sound “jay,” in an effort to explain that we ate vegetarian. We now suspect that what we were actually saying was, “Vegetable…vegetable…understand…vegetable…understand…understand…”