I have lived in Germany during many periods of my life (adding up to 3 years) and German language is still difficult for me even although I can speak and have s

I have lived in Germany during many periods of my life (adding up to 3 years) and German language is still difficult for me even although I can speak and have simple conversations in German, I'm not able to write letters with the required formality in that language. Where I live (medium-size town in west Germany) few people speak English. If I was to take a job in say, The Netherlands, I feel that at 39 yo, I have no chance of learning a fourth language (I already speak ES, EN, DE) with the needed proficiency to integrate by purely speaking Dutch. Therefore, I hope that language barriers are lowered in favour of a real European integration.