This Forum challenges the generally accepted position in the linguistic sciences—conscious or not—that monolingualism and nativeness are essentially synonymous in an exclusive way. We discuss two consequences of our position that naturalistic bilinguals and multilinguals exposed to a language in early childhood are also native speakers: (i) that bi-/multilinguals have multiple native languages; and (ii) nativeness can be applicable to a state of linguistic knowledge that is characterized by significant differences to the monolingual baseline.

The focus of the present paper is on the measurement of lexical richness. Lexical richness is often measured either by the traditional type‐token ratio (TTR) or by its square root variant, the index of Guiraud. The disadvantages of these measures, especially those of the TTR, are well‐known. In this paper we propose two measures (Advanced TTR and Guiraud Advanced) that have clear advantages over the traditional measures. These two measures combine characteristics of type/token related measures with the notion of different layers of frequency/productivity in the lexicon (see Laufer and Nation 1995). We computed indices for the lexical items used in an oral text production task by two groups of Turkish‐German bilinguals. One group has a German dominant bilingual competence; the other group consists of Turkish dominant bilinguals. It will be shown that the proposed measures for advanced lexical richness trace the characteristics of the bilingual profiles of the groups of subjects better than the traditional measures. Since the two languages involved in this study are typologically quite different, the additional technique of standardizing scores (z scores) was required to draw comparisons between the two languages. The conclusion is that the two proposed indices of advanced lexical richness, and especially the Guiraud Advanced, yield the clearest results. The new measures can be readily computed and are useful in the context of linguistic research as well as in classroom settings.

Many researchers have tried to assess the number of words adults know. A general conclusion which emerges from such studies is that vocabularies of English monolingual adults are very large with considerable variation. This variation is important given that the vocabulary size of schoolchildren in the early years of school is thought to materially affect subsequent educational attainment. The data is difficult to interpret, however, because of the different methodologies which researchers use. The study in this paper uses the frequency-based vocabulary size test from Goulden et al (1990) and investigates the vocabulary knowledge of undergraduates in three British universities. The results suggest that monolingual speaker vocabulary sizes may be much smaller than is generally thought with far less variation than is usually reported. An average figure of about 10,000 English word families emerges for entrants to university. This figure suggests that many students must struggle with the comprehension of university level texts.

The aim of this article is to show how measures of lexical richness (Guiraud, 1954; Malvern, Richards, Chipere, & Durán, 2004) can be used to operationalize and measure language dominance among bilinguals. A typology of bilinguals is proposed based on these measures of lexical richness, and the validity of the typology is then investigated in an empirical study among two groups of bilingual informants with different language dominance profiles (25 Dutch—French bilinguals from Brussels and 24 French—English bilinguals from Paris). The most important advantage of the proposed operationalization is that it allows researchers carry out precise measurements of bilingual ability in languages or language varieties for which no standardized tests exist and that these measures can be calculated on oral data that have been collected in an informal and unobtrusive way, in a naturalistic setting.

This study contributes to ongoing discussions on how measures of lexical diversity (LD) can help discriminate between essays from second language learners of English, whose work has been assessed as belonging to levels B1 to C2 of the Common European Framework of Reference (CEFR). The focus is, in particular, on how different operationalizations of what constitutes a ‘different word’ (type) impact on the LD measures themselves and on their ability to discriminate between CEFR levels. The results show that basic measures of LD, such as the number of different words, the TTR (Templin 1957), and the Index of Guiraud (Guiraud 1954) explain more variance in the CEFR levels than sophisticated measures, such as D (Malvern et al. 2004), HD-D (McCarthy and Jarvis 2007), and MTLD (McCarthy 2005) provided text length is kept constant across texts. A simple count of different words (defined as lemma’s and not as word families) was the best predictor of CEFR levels and explained 22 per cent of the variance in overall scores on the Pearson Test of English Academic in essays written by 176 test takers.