This is the final phase — and it's a lifelong one. The goal is to close the remaining gap between a highly fluent non-native speaker and someone who grew up in the language. That gap exists in three areas: vocabulary, cultural depth, and the kind of deep intuitive connection that comes from living in a language for decades.
Not everyone needs or wants to reach this level. If functional fluency is your goal, you've already achieved it. But if you want to be indistinguishable from a native speaker — not as a performance, but as a reality — this is the path.
Be honest with yourself about what this requires. Native speakers have spent their entire lives in the language. They've had tens of thousands of experiences, read hundreds of books, and had millions of conversations. You're compressing decades of lived experience into several thousand hours of deliberate effort, probably less than 10% of the time a 29-year-old native speaker has spent.
It's worth noting that this is basically impossible to do if you don't live in a country or comunnity that speaks the target language.
Vocabulary expansion — A college-educated native speaker knows 15,000-20,000 words (depending how you count). You probably know 10,000-12,000 at this point. The remaining words aren't the "common" ones — they're the long tail: the word for shoelace, the name of that specific type of wrench, the verb for what birds do when they clean their feathers.
The best way to learn them is to live your life in the language and actively notice when you don't know something. Be exessively curious. Ask the natives around you about every little thing. "What was that word?" "Why'd you say it like that?" "What would you call this thing?" Carrying a notebook around with you to write down new things can be helpful.
Reading widely is the single most effective way to expand your vocabulary at this level — books use a far wider range of words than spoken language.
Cultural literacy — Native speakers share a body of cultural references: childhood TV shows, historical events from their country's perspective, proverbs, jokes, songs, and shared experiences. You can't absorb this passively — seek it out. Watch the shows that everyone in the culture grew up watching (especially those in your age/peer group). Read the books that are assigned in school. Learn the history from the perspective of native sources.
Fluidity and depth — Being able to describe a complex feeling or thought without hesitation, in multiple ways, with the exact right nuance — this is what separates "very fluent" from "native." The only path is time, practice, and a deep commitment to using the language as your primary mode of thought and expression. Chorusing, shadowing, and extensive reading all help, but there's no shortcut. This takes years.
Emotional connection — Native speakers don't just use their language. They feel in it. Jokes land differently, sad stories hit harder, and certain words carry weight that doesn't translate. Building this kind of connection requires deep engagement with the culture and the people who speak the language.
This phase doesn't have a strict routine. You're living in the language. But here's a general framework:
You're "done" when:
Realistically, this phase takes years. But at this point, the language isn't a project anymore — it's part of who you are. You'll never truly be done learning (poetic, isn't it?)
This final phase acknowledges the limitations of the traditional "native speaker" concept, a concept challenged by Cook's (1992) work on multicompetence. Cook argues that highly proficient L2 speakers develop a distinct and valid form of linguistic competence — different from monolingual native speakers, but not deficient. The goal of this phase isn't to erase that difference but to close the gap to the point where it no longer matters in practice.
The vocabulary targets reflect Nation's (2001) research on native-speaker vocabulary size. Goulden, Nation, and Read (1990) estimated that university-educated native speakers know approximately 17,000–20,000 word families. The 15,000+ target for this phase reflects what research suggests is sufficient for high-level literacy and sophisticated discourse — close enough to native-like knowledge that gaps in lived experience, rather than vocabulary, become the primary remaining limitation.