I found this to be a real issue. Native speakers value stuff that I get right with no effort, like getting "its" and "it's" right or usage and spelling of "complicated words" (most of latin and greek origin). Furthermore, most native speakers (e.g. "current undergraduate college students") have the tendency to write the way the speak (or using complicated words that makes is look like I have control over this language while I obviously don't: excessive colloquialism).

I struggle putting the words in the right place, getting articles right, controlling the subtle nuances of tone the make the difference.

I have troubles writing less and yet be understood.

Please don't say that today your kids don't know their mother tongue, that's not true. They just struggle with adapting to formal language.

EDIT: in case you find that in this particular text there are no significant issues, keep in mind that this is after many years of using the language professionally and after one year of living in Ireland.

Although native-English speakers are always nice enough to tell me that my English is "good enough" to be understood, there are times that I feel uneasy with myself, because I just lack the practice to be able to communicate fluently in English.

Similar feelings here. I am Spanish, and work in Ireland since 4 years ago, so I have to communicate in English.

Even if people had told me quite a lot of times that my English is very good, that they've never have problems understanding me, I still can feel all the extra effort that I have to put into it, as well as being aware of most of the grammar or pronunciation mistakes I do.

Of course, practice is everything. I am clearly way more relaxed now than I used to be. But I still have to take some seconds from time to time to phrase correctly. On the other hand, I do that as well on Spanish. Communicating is hard!

I guess that some Dunning-Krueger effects works here. You are aware of your limitations, even if they are not that big, and that stings.

I have exactly the same problem, a little bit aggravated by the fact that I seem to be a little bit dyslexic and sometimes I type something but I read something completely different.

People tend to be nice, so I just try to get the message through and don't think too much about it :)

It's not that it's "good enough." It's actively better than most of the people I communicate with. Don't sell yourself short :)

If you ever want someone to speak English with, I'm Arthur Colle, and you can find me at facebook (dot) com (slash) arthurcolle

:)