I've been in many a conversation where an ESL teacher complains that their English vocabulary is shamefully depleting. They don't say it in those words, of course, but use feebler phrasing along the lines of "my English gets worse the more I teach it. What the heck?"
I imagine that while many jobs out there enable workers to use their most flowery million-dollar words in intimidating emails and reports and such, paring down language to its simplest terms is crucial for ESL teachers. How else can we explain grammar points and define new vocabulary to students who are relatively new to the English language? Drawing stick-men in various actions, despite being cute and all, only gets you so far.
Thus, ESL teachers develop the skill of using little words for big topics. The drawback seems to be that this talent becomes a condition; one that bleeds into our non-work lives.
The solution? Well it's tough to say. I can smugly proclaim that this has never afflicted me, since I read the dictionary for fun and seem to have a built-in Blarney Stone mechanism that keeps me a-chatterin' day and night. But here are some thoughts:
a) Read read read! Find books by great clever loquatious writers whose sentences are long and vivid. Think Austen over Hemingway. And don't blame your overseas status, I know that every sizeable city on Earth has some Penguin Classics kicking around.
b) Study up on your field. You don't have to limit yourself to reading ESL textbooks in order to stay fresh in the biz. Go online or join an e-mailing list and learn about teaching methodology, new research on foreign language acquisition, interviews with the smartypantses of the industry. It'll keep you ahead of professional lingo too, so you can save yourself from depleted-vocabulary conversations with coworkers at least.
c) Do a daily crossword. They help you flex some mental muscle and, apparently, ward off Alzheimer's. You can find these on most major newspaper websites.
d) Keep in touch with your brainiest friends. I have an Aunt who is frighteningly witty, and every email I compose to her goes through cycles of drafts and edits because she sets the bar high. If emails are a casual thing in your books, then keep a journal. We often try a little harder to form tight, concise sentences when we put pen to paper, because of the permanence of the act.