Well, I can talk to my two year old in Dutch and he understands me perfectly. He doesn't correct me. He doesn't do what I ask either, because he is two and his way is better. So my Dutch language skills are better than that of a two year old. Actually he is nearly three. So, minor correction, my Dutch language skills are better than an almost three year old.
I can talk to my four year old in Dutch and he understands me. What I say quite often has no consequence, simply because he is four and he knows better. However, I do know he understands me and he also doesn't correct me. I do sometimes have to correct his de or het when he says something. It's not often mind because most of the time I am not actually sure if the noun should have de or het in front of it, so I let it slide. He also says "hij hebt..." a lot and I absolutely correct that because that is something I do know. And just so you know, should you ever hear him say that, he hasn't picked it up from me. In fact, we have no idea where he has picked up that from. Anyway, moving on. My Dutch language skills are definitely better than those of a four year old.
I can talk to my seven year old in Dutch and he understands me perfectly. But he does
From these conversations I deduce that my Dutch is nowhere near as good as a forty year old's command of Dutch.
So there you have it. The level of my Dutch language skills lies somewhere between that of a seven year old and that of someone who hasn't yet celebrated their fortieth birthday. A scientific approach it may not be, but my goodness it's accurate!
Based on my utterly amazing measurement system, what level is your second language currently at?