Yes, you can absolutely learn to speak Dutch fluently after 40. Age can slow down some aspects of language learning, such as accent acquisition and raw memorization speed, but it does not prevent fluency. Many adults reach B2 or C1 in a second language later in life, especially when they live in the country and use the language daily.

At B1, you are past the beginner stage. The plateau you feel is normal. Progress from B1 to B2 is less about new grammar and more about volume, automaticity, and confidence. Your two private lessons per week and group conversation are good foundations. To break through, you likely need more hours of active Dutch use, not just more study.

What research and learner experience suggest:

  • Adults learn grammar and vocabulary faster than children in the early stages.
  • Children usually win on accent, but a clear, understandable accent is a realistic goal for adults.
  • Fluency is mostly about how many hours you spend using the language, not your birth year.
  • The biggest adult advantages are motivation, strategy, and life experience.

Practical steps for your situation:

  1. Increase active speaking hours. Aim for at least 10 to 15 hours per week of real conversation, not just lessons. Join a hobby group, volunteer, or take a job where Dutch is spoken.
  2. Get feedback on recurring errors. Ask your private teacher to track your top five mistakes and drill them until they disappear.
  3. Read and listen daily. Dutch news, podcasts, and books at your level build vocabulary and sentence feel.
  4. Shadow native speakers. Repeat audio out loud, copying rhythm and intonation. This helps fluency and pronunciation.
  5. Set a measurable goal. For example, pass a B2 exam or give a 10 minute presentation in Dutch within six months.
  6. Accept the plateau. It often means you are consolidating. Change your routine rather than quitting.

Honest tradeoffs: You may always have an accent. You may need more repetition than a 20 year old. Progress can feel invisible for weeks, then jump. That is normal.

If you want structured help, look for a coach who specializes in adult learners at B1 to B2 and who gives speaking heavy lessons. Dutch Fluency is one search term you might use, but compare teachers by trial lessons and reviews. You are not too old. You are at the stage where consistency and real conversation matter most.