Ultimate Attainment
Ultimate attainment refers to the end-state grammar a second-language learner reaches after the acquisition process has effectively stopped changing. It is the dependent variable in much of the research on age effects, aptitude, and the critical period, because the claim that adults cannot reach native-like competence has to be cashed out as a claim about the stable long-run outcome, not about the rate or route of acquisition.
Why It Is Hard to Measure
Three problems make ultimate attainment slippery. First, you need learners whose acquisition has plausibly plateaued: typically long-residence bilinguals with decades of L2 use. Second, you need tasks sensitive enough to separate genuinely native-like grammar from the highly proficient L2 grammar that passes for native in casual listener judgements. Third, you need a baseline of monolingual native speakers that does not itself show unexpected variation.
Near-Native Is Not Nativelike
The sharpest methodological move in the literature is Hyltenstam and Abrahamsson's scrutinised-near-native paradigm. In a 2009 Language Learning study, they took L2 Swedish speakers who had been judged as native by listener panels and ran them through morphosyntactic and phonetic tasks designed to be sensitive to subtle non-native behaviour. None of the late starters (ages of onset after 12) performed within the native-speaker range on the scrutinised tasks, even though they had passed the listener check. The conclusion: listener perception routinely overestimates nativelikeness; detailed linguistic scrutiny separates near-native from nativelike.
What Constrains the Outcome
The current literature attributes variance in ultimate attainment to:
| Factor | Evidence |
|---|---|
| Age of onset | Strong and consistent negative correlation with nativelikeness |
| Aptitude | Some late starters with high aptitude approach but do not reach native range |
| L1-L2 typological distance | Subtle L1 influence remains detectable even in advanced learners |
| Quantity and quality of input | Necessary but not sufficient for nativelike outcomes |
| Bilingualism itself | Controlled for in Bylund, Abrahamsson & Hyltenstam work; age effect survives |
Theoretical Stakes
The ultimate-attainment literature is the empirical ground on which the Critical Period Hypothesis and the Fundamental Difference Hypothesis stand or fall. Counter-examples (a genuinely nativelike late starter) would damage both. The Stockholm programme's contribution has been to raise the bar for what counts as a counter-example, which is why the literature increasingly distinguishes "passes for native" from "performs within native range on scrutinised tasks."
References
- Abrahamsson, N. & Hyltenstam, K. (2009). Age of onset and nativelikeness in a second language: Listener perception versus linguistic scrutiny. Language Learning, 59(2), 249–306.
- Bylund, E., Abrahamsson, N. & Hyltenstam, K. (2012). Age of acquisition effects or effects of bilingualism in second language ultimate attainment? In G. Granena & M. Long (Eds.), Sensitive Periods, Language Aptitude, and Ultimate L2 Attainment. John Benjamins.
- Hyltenstam, K. & Abrahamsson, N. (2003). Maturational constraints in SLA. In C. Doughty & M. Long (Eds.), The Handbook of Second Language Acquisition. Blackwell.