Exploring variation in English as a lingua franca: Multivariate analysis of modal verbs of obligation and necessity in the VOICE corpus

The modal verbs of necessity and obligation, a testing ground of grammatical change, have been shown to exhibit change and variation in world Englishes. Previous studies have primarily concentrated on English as a native language (ENL) and English as a second language (ESL) varieties. The present study extends this line of research and explores variation in modal verbs of necessity and obligation in English use as a Lingua Franca (ELF). Descriptive statistics indicate that ELF resembles American English and also shares similarities with ESL varieties. In addition, ELF further exhibits divergence from both ENL and ESL varieties that arises in multilingual interactions. The multivariate analysis of this study employs mixed-effects logistic regression on the use of must and have to. Integrating social and linguistic factors, this analysis exploits metadata gathered from the VOICE corpus, which has thus far been underused. The results of the inferential statistics indicate that the same sociolinguistic factors that influence the variation in ENL and ESL varieties also shape ELF grammar. These findings not only bring ELF closer to other English varieties but also demonstrate the advantage of studying ELF from a variationist sociolinguistic perspective.