Lectures in English

I’m receiving regularly some offers to deliver lectures or public speeches in English. Until now I was always refusing them, because wasn’t feeling myself ready enough, while my English level was remaining shamefully low for that. But there comes a time to break the rule and overwhelm my own fear. 

The source of the fear itself is my worship to a language, either my own or foreign. You cannot pretend to teach or even to make a responsible public statements using a language in which you are not proficient enough. English, however, is for many people a remarkable exception in many cases — due to the fact that it is a “default language” for most of international conversations, many people use it to express themselves in public speeches despite their pitiful pronounce and vocabulary and grammar etc. But for me it’s a kind of going against the grain — if you want to present yourself as an expert, your core instrument of self-expression MUST be quite professional as well.

So, it’s a really difficult choice. Need your advice.