Few speak English well.
Far fewer write well.
That’s what I’ve seen time and again among people from multiple walks of life.
(Note that speaking here refers to regular conversations we hold and not to public speaking. And writing doesn’t mean SMS or quick 2-3 line emails. It means writing paragraphs, essays, reports, proposals, and the like.)
I’ve spoken to and reviewed application essays for international MBA programs from people working in reputable organizations, including multinational companies. I found most to be fluent speakers, but, by and large, only few could write well. And here I’m not talking of people working in any random organization. I’m talking of top-notch organizations, where we expect employees to have impeccable speaking as well as writing skills.