Post written by François Grosjean.
I have always been fascinated by how second / foreign / world language teachers juggle between their lives as bilinguals and their profession as teachers of a language, culture and literature. This may come from the fact that I started my career teaching English to French students and that I too had to handle this duality.
Those who teach a language other than the country's main language(s) are usually bilingual in that they use their two (or more) languages on a daily basis. But they are special bilinguals in a number of ways.
First, some may not often use the language they teach outside the classroom since they may not have a need for it in everyday communication. Regular bilinguals usually have several domains of use for their different languages.
Second, most language teachers have insights into the linguistics of the language that regular bilinguals simply do not have. They have to explain German morphology and word order, the rules of the past participle in French, the difference between "ser" and "estar" in Spanish and so on, when a regular bilingual would have a hard time doing so. Any normal bilingual who has replaced a language teacher knows first hand how difficult it is to suddenly explain a complicated aspect of a language that she usually speaks without giving it a second thought.
A third difference is that language teachers have both their languages active when they teach - they are in a bilingual mode (see a post on this). Thus, as they are using one of their languages overtly in class (e.g. Spanish), they also have their other language (e.g. English) ready to intervene in case someone asks a question in it or produces a code-switch (see here). But they rarely allow themselves to intermingle their languages and they may well correct those who do.
This is an interesting predicament. So as not to "set a bad example", they may not resort to the other language even though it could facilitate communication. However, as users of the languages themselves, and in private, they may well do so. This said, I have known some language teachers who refrain from intermingling languages completely so as not to slip into this mode when they are teaching.
A fourth difference is that they are usually true admirers of the second language they teach - at least of its standard variety - and they have a real love for its culture(s). They convey this passion to their students some of whom become fascinated in turn. This may lead the latter, one day, to visit a country where the language is spoken and even to live in it. The enthusiasm many teachers show is not the norm in regular bilinguals who spend less time thinking and talking about their languages and their cultures. Everyday aspects of life are simply too demanding of their time and attention.
Finally, many language teachers simply do not believe they are bilingual. This is true of many regular bilinguals but maybe more so in the case of teachers. They hold a very strict view of what it means to be bilingual such as to have complete and equal fluency (spoken and written) in your two or more languages, having no accent in them, even having grown up with all languages.
When I speak to language teachers who feel this way, I try to convince them that they are indeed bilingual even though they do have specific characteristics. I also tell them that despite the demanding job that they do daily, they are laying the foundations of interlingual and intercultural communication among their students - something they can certainly be proud of.
Grosjean, François. Special bilinguals. Chapter 13 of Grosjean, François (2010). Bilingual: Life and Reality. Cambridge, MA: Harvard University Press.
"Life as a bilingual" posts by content area: http://www.francoisgrosjean.ch/blog_en.html
François Grosjean's website: www.francoisgrosjean.ch