Add to that the fact that I spend a lot of time talking with people abroad, often people I have never met, and for whom English isn't their first language, and there is a lot of scope for misunderstanding.
So my secret work weapon is to always check whether people really are saying and understanding the same thing. Maybe I'm hypersensitive to this because I studied languages (French, Spanish and Portuguese) for my degree and lived abroad as part of my course. I remember a very frustrating conversation with my Spanish flatmate about the dead cockroach (cucaracha) I had found. He didn't seem to want to accept that this was the case until I realised his confusion was due to me actually telling him about the dead cucharada (spoonful).
Ironically, I find the greatest need to check we're all really saying the same thing is with my 'English'-speaking marketing colleagues in the US.
It seems we use the same small set of words to refer often to very different things, so it's a frequent occurrence to hear me say 'Can I just clarify ...' And if all else fails, it's true that a picture speaks a 1000 (foreign) words.