Deutsch sprechen? Steig ein!

You beg my pardon why?
Do you not think you can improve?

Of course I can improve, but you said ' because you could improve a hell of a lot' I was under the impression that my English was fairly advanced....

You could improve a HELL of a lot.
That's NOT a criticism, just a fact. What level have you reached - which exams have you taken?

In what way could I improve?!

What you write isn't bad, but you don't use much of a range of tenses or grammatical structures. Your vocabulary could be considerably enlarged. Don't be offended - I haven't met you, and maybe what you write here isn't indicative of your best English. It just seems rather basic to me, that's all.
But answer the question: what level have you reached?

What do you mean by level?

Exams. Have you taken any? TOEFL, First Certificate, CAE, IELTS?

Well there's my ' Highschool ' exam and I did a couple of 'Anglia' exams...

I don't know Anglia, but I doubt that Dutch High School is a very high level. I've taught CPE, the Cambridge Certificate of Proficiency in English, which is the level AFTER Advanced English. I've taught a woman who lived in the US for 2 years. I'm very experienced with advanced English, and I'm not convinced you're there yet!
Why don't you check out CAE and CPE on the net, old exam papers, and see how 'easy' you find them? BTW, native speakers have failed the CPE.

I will try those , I'm suprised really that you haven't heard about Anglia
http://www.anglia-examinations.co.uk/introduction/test.htm

Dutch 'Highschool' offers a very good English course. I had English for 6 years still have it but in a different way

And I will try those old exams ..

I can't seem to find any 'old'exams on the web...

I've HEARD of Anglia, but never taught it myself.

I can't seem to find any 'old'exams on the web... >>
No, I can't at the moment either, annoyingly! Anyway, if you're interested I can try to sort something out (we have loads of them at work)

Nah, Ill find it out myself. :)

which level of Anglia exams did you pass?

Still this whole, 'you could improve a hell of a lot' comes as a suprise , I've never had any problems with expressing myself in English at all.And I doubt you can make a good analysis of my vocabulary since you only know me for what?2 weeks? ;)