"Start work" vs "start working"

"Start work" is the idiomatic expression (at least in AmE) for showing up at your place of employment. You may or may not do anything once you arrive. "Start working" means initiating some endeavor. Thus: "I start work at 9A, but I don't really start working until 9:30." – deadrat

My feeling is that for a job, the more natural choice is "start work." A new hire would respond to a question about a start date at the company with "I'd like to start work as soon as possible." A building contractor would make the same choice when talking to a homeowner about a project. A general activity would take "starting"+on: "Cleaning out the basement will be a chore. I need to start working on it soon." I doubt I could document that as a general rule, and remember I speak the American kind of English. – deadrat