The problem is that English speaking people rarely learn other languages and therefore don't have much skill at communicating with people who are not fluent in

The problem is that English speaking people rarely learn other languages and therefore don't have much skill at communicating with people who are not fluent in English. Communication is a two-way street. When I was working in the UK in multinational companies, the employer put a fair amount of emphasis in using International English in all communications. For those of us with an interest in literature this was a bit difficult because our heads were filled with flowery language. If you have any second language skill at all, then you can probably deal reasonably well with 3/5 English speaking folks as long as you are careful to avoid slang and write your emails in clear International English.