Q. A colleague said to me, “She is based out of Chennai.” I perceived this as “She is not based in Chennai, but somewhere else.” When I questioned this, she said she meant that the person is based in Chennai. Is this standard English?
A. Oddly, yes. It is a standard idiom, if not formal English. It’s often said that navigating prepositions is the trickiest part of learning English; this is a good example. “I work out of my home” does mean “I work at home as a base” (even if that involves traveling). Perversely, it’s the opposite of “I work outside the home,” which means working somewhere else. Being “based out of” is a similar concept, of someone having a home base that they work “out of” or “out from.” Obviously, there is potential for great misunderstanding in the use of this expression. It’s one of many reasons why the use of formal English for professional communications is still a good idea.