Your current approach is a solid foundation, but to reach C1 or C2, you need to shift from passive consumption to active, deliberate practice focused on nuance and production. The key is to systematically target the gaps between B2 and advanced levels: precision, register, idiomatic fluency, and the ability to handle abstract or professional topics with ease.

Your YouTube immersion is excellent for maintaining input, but it's not enough on its own. To progress, you must engage in output activities that force you to stretch beyond your comfort zone. The translation exercise you're doing is a good start, but it can be made more effective. Instead of translating random complex sentences, focus on specific problem areas like collocations (e.g., "make a decision" vs. "do a decision"), phrasal verbs, and subtle differences between similar words (e.g., "affect" vs. "effect"). Use a good learner's dictionary (like Cambridge or Oxford) to check usage and example sentences.

A more powerful routine would include these elements:

  1. Deliberate reading and listening with active recall. Read articles from quality sources (e.g., The Guardian, The Economist, BBC News) that cover topics you find interesting. After reading a paragraph, close the page and summarize it aloud in your own words. Record yourself and listen back to catch errors or unnatural phrasing. Do the same with podcasts or YouTube videos: pause every 2-3 minutes and retell what you just heard.

  2. Shadowing and pronunciation work. C1/C2 requires near-native rhythm and intonation. Choose a short audio clip (2-3 minutes) of a native speaker you like. Listen once, then repeat the sentences out loud simultaneously with the speaker (shadowing). Focus on matching their stress, pitch, and linking sounds. Do this daily for 10 minutes.

  3. Structured writing and speaking practice. Write a daily journal entry of 200-300 words on a specific topic (e.g., explain a concept from your field, argue a point of view). Then use a tool like an AI language model or a language exchange partner to get feedback on grammar, word choice, and style. For speaking, find a conversation partner (e.g., through iTalki or Tandem) at least twice a week and ask them to correct your mistakes in real time.

  4. Expand your vocabulary systematically. Instead of memorizing lists, learn words in context. For each new word, write down its definition, an example sentence, and a related word (synonym, antonym, or collocation). Review these using spaced repetition (Anki is a free, proven tool). Focus on academic and professional vocabulary (e.g., from the Academic Word List) and idioms.

Tradeoffs to consider:

  • Time vs. focus: 60-90 minutes daily is great, but quality matters more than quantity. A focused 30-minute session of active practice (e.g., shadowing or writing) is more valuable than an hour of passive YouTube watching.
  • Translation vs. immersion: Translating from Spanish can reinforce errors if you rely on word-for-word equivalence. Instead, try to think directly in English by describing situations or ideas without translating.
  • Self-study vs. feedback: Without a teacher or native speaker, you risk fossilizing mistakes. Invest in occasional professional feedback (e.g., a 30-minute session with a tutor every two weeks) to catch blind spots.

Concrete next steps for this week:

  • Pick one article from The Economist and do the summarize-aloud exercise.
  • Start a daily 10-minute shadowing routine with a YouTube video of your choice.
  • Write a short opinion piece on a current event and ask a language partner or AI to correct it.

Remember, C1/C2 is about control and flexibility, not just vocabulary size. You need to be comfortable with irony, humor, and subtle shifts in tone. Keep pushing yourself to produce language that is not just correct but also appropriate for the context.