Alex Case wrote:While what you have heard is very generally true, Spain is the only country I have been to where schools quite often asked for a particular level of Spanish in their job ads or asked about your level of Spanish in the interview.
That is probably a very accurate statement Alex - it would also be interesting to know if the schools in north-eastern Spain require TEFFLers to know Catalan

A good school wishing to attract quality teachers will strive to produce its contracts and other documentation at least in English.
A TEFL teacher cannot forcibly be expected to have any command of the language of his/her host country.
I worked in Thailand for many years before I attained any degree of fluency in its difficult language. Also, to learn the pictographic languages of East Asia would pose a serious challenge to most people just wanting to teach there for a while, as I'm sure Alex certainly knows from his wide experience there; if such a requirement were enforced it would be the end of Asia as a TESOL destination for native English speakers.
However, a basic knowledge of any second language will certainly help a teacher to understand more about the constructs of language acquisition.
Much of the world's population is bilingual from birth, especially those in large or tribal countries that use one language as the national lingua franca, while in the provinces quite different local languages are used. India is
the classic example, the vast Russian Federation is another, and I'm sure a similar situation exists in China. Even in the much smaller country of Thailand a fairly different language, a dialect of Lao, is spoken in the region where I live, but the people are bilingual, and there are a dozen or so tribal languages used extensively in other parts of the country, while in eastern Thailand the local language is a version of Khmer (Cambodian).
Even in Wales and Scotland many British natives are bilingual. The human being is surprisingly capable of learning several languages, and when not needed for academic purposes, no particularly high level of cognition is required. Anyone who stays in a country long enough will learn some the local language automatically - it's inevitable.