I'd dare claim the opposite: A foreigner's English skill may be way better than that of a native American, born in Ohio, living in the US for his entire life.
- And an apology in advance, this response got rather long!
Why do I think that? (And I don't mean to step on anyone's foot here)
If you learn a language as a child, you mainly do so by mimicking your parents, close relatives, and friends. This may also include any grammatical errors or misuse of idioms. In school, you start learning about grammar, tenses, and the interconnections between them. At this point, many of us aren’t even paying attention anymore. After all, we do know how to speak, right? We did it for the past 10 years or so.
I’m a German and didn’t learn English until I reached 5th grade (first year of middle/high school in the German system). I had seen and heard English before, but not to a comprehensible extent. I quickly took a deep interest in learning and was among the best in our class. I enjoyed it. And I enjoyed our English teacher, who was one of the kindest teachers I had the honor of meeting.
I also was a fan of many English bands, though I only slowly, step-by-step, learned to understand the actual lyrics over the melodies and “cool” guitar riffs.
A whole new world opened up to me and songs I liked for entirely different reasons started to fascinate me not for the assemble, but the deep message they tried to convey.
Once I finished high school, I entered a vocational school to train a profession, which would later carry me all across Europe: I trained to become a truck driver and had to learn a lot more business-oriented English in order to be viable for international transportation.
Fast forward: I am now living in Japan. I’ve been working for the US-military over the past years before becoming an independent freelancer and starting my own business as a writer.
Apart from using English professionally, my private life has shifted a lot, too. Everything I do, I do in English. Games, movies, books, chatting with people. Everything. I do think and monologue in Japanese though. That kinda sneaked its way into my head over the years, since my wife does not speak English proficiently enough to use it as our main means of conversation.
Of course, education does play an important role too, but I wouldn’t consider myself being well educated. I personally spend a lot of time with Wikipedia to read about anything and everything, from nuclear fission to history. Not everyone may be as involved in the English language as I am.
But since we came from the outside and had to learn this language away from the impressive memory capacities and ease of learning a toddler may have at his disposal, we dissect a language much more in order to remember the rules.
So I strongly believe that a foreigner having learned a language this way is more sensitive to smaller rules and nuances that a native speaker may not even recognize or realize.
The same goes the other way around. As a German speaker, I know exactly which of the three articles to use for a noun (Der, Die Das). I also know that it has something to do with “Genus” (gender) of the word at hand. But I couldn’t for the life of me explain to you exactly why this rule exists, how it was made up or why it’s necessary to have it. I bet that any American who had studied the German language could sit down with me and explain it better than I could.
I consider my English pretty solid. I can talk, think, work, and write in English. Heck, I even wrote and published an article about grammar here on Medium. I’m neither a native nor do I have any form of degree or qualification in English literature or the likes.
I’m just thorough when learning this language. And I believe that most people approach German in the same manner.
As long as you are picking on the details and thoroughly analyzing a language, you can become very proficient with it. To that end, it doesn’t even matter whether you are a native or a foreigner learning it as a second language.
I’d urge all foreigners to keep writing in English, even if their current level does not meet their own expectations or seems difficult to sustain. Practice makes perfect. Just keep at it and don’t give up.
If you feel uncomfortable writing in English here on Medium, for example, I’d suggest looking into Grammarly, a free tool to help you fix mistakes along the way. It’s pretty handy and I’d even recommend it to people, who like myself, consider their English near perfect. There’s always an error or typo we’re unaware of. Nobody’s perfect. As much as we’d like to be.