The jump from B2 to C1 usually comes from three things: massive amounts of input at the C1 level, deliberate output practice with corrective feedback, and a shift from general Dutch to the specific registers you actually need. It is not about learning more grammar rules but about automating the ones you already know and expanding your active vocabulary and collocations. Most learners who break through do so by combining structured production (writing and speaking) with timely correction, often from a tutor or language partner, and by immersing themselves in challenging, authentic material.
At B2+, your comprehension is strong, so the bottleneck is production. You need to make your errors visible and fix them systematically. Keep an error log: every time you write or speak and make a mistake, note it down with the correct version and a short explanation. Review it weekly. For writing, use a tool like ChatGPT to generate C1-level sentences and then rewrite them yourself, but also get human feedback on your own output. A tutor or a language buddy who will correct you is invaluable. If you do not have access to one, consider a structured course or a platform like Dutch Fluency that focuses on advanced production, but evaluate any option by checking whether it includes personalized feedback and speaking practice.
For speaking, find a conversation partner who will gently correct you. If you are in the Netherlands, join a taalcafé or a meetup group. Online, there are exchange platforms. Record yourself speaking on complex topics and transcribe it to spot errors. Shadowing native speakers (repeating after them) helps with pronunciation and fluency.
Input should be challenging: listen to podcasts on current affairs, watch documentaries, read opinion pieces and literature. Pay attention to collocations and fixed expressions, not just individual words. Use a spaced repetition system to learn chunks, not isolated words. For grammar, do not re-study basics; instead, target the specific structures you get wrong, like subordinate clause word order, the use of 'er', or complex verb tenses. Use a grammar reference to check your errors as they come up.
Finally, set specific goals. For example, write a 200-word essay each week and get it corrected, or have a 30-minute conversation with a tutor weekly. Track your errors and measure progress. Be patient: the B2 to C1 gap often takes 6 to 12 months of consistent, focused effort. The key is to move from passive exposure to active, corrected production.