Can I be fired or get in trouble for this?

No an English person will not complain ,if they do the manager will just apologize you won't get in trouble also I'm from New Brunswick most bilingual staff where these a href="http://www.pch.gc.ca/special/guide/info/107-eng.cfmpins" rel="nofollow"http://www.pch.gc.ca/special/guide/info/…/a so a customer knows that a person speaks both .