I was born in America, raised learning English, and to this day, my written skills are nowhere near perfect. Nor are my verbal skills. I am constantly writing and rewriting sentences because the intangibles of communications, such as tone, style, prose, format, are
extremely important and often overlooked. Not to mention, my grammar after 29 years is still far from perfect.
I've attempted and now partially understand, read, write, and speak Spanish, Swedish, German. Having experienced all of the intricacies of other languages, I don't envy those who are far behind me trying to make it in an English.
That being said, what's the lesson learned, or probably more apt - what's the solution? This is why firms like YC exist, is to provide support to founders that lack all of the acumen (and trust me, there's a lot) that is required for 21st century business leaders. There's often a meta discussion here on HN about the "technical co-founder vs business co-founder". This is one area where having a business co-founder with great communication skills is a great reason to partner up with that person. Unfortunately those who do lack communication skills often find it difficult to understand those who do have good communication skills.
I wish I could help somehow...