Even slight misinterpretation of English can cause devastating consequences.
Look at Tenerife, not the obvious one but a little known one of the Dan Air 727 CFIT back in early 1980.
There were of course other factors (and I am well aware of them), however the controllers inability to articulate correctly rather critical information (misinterpreted by the crew) led to around 150 people losing their lives, instead of enjoying what was going to be a summer holiday in the sun.
Words (or lack of them) can kill.