This study examines how higher-rated language use during second language speaking and writing performance can be predicted by linguistic features found in speaking and writing samples while controlling for linguistic knowledge. Findings provide similarities and distinctions between speaking and writing in language use including lexical, syntactic, and cohesive features.
Proficient L2 speakers and writers tend to have greater linguistic knowledge, but actual language use across speaking and writing modalities likely differs. This notion, while generally accepted, has not been strongly examined empirically. To examine how language use is differentially aligned between L2 speaking and writing performance, this study examines the potential to predict higher-rated language use during L2 speaking and writing using linguistic features while controlling for linguistic knowledge. L2 speaking and writing data were collected from 295 Spanish- and Portuguese-speaking learners of English. The writing task asked learners to produce an opinion essay or letter, while the speaking task asked learners to provide a subjective response to an interviewer’s question. Scores for learners’ language control/range were collected for each speaking and writing sample. Linguistic knowledge was measured through multiple-choice vocabulary and grammar items. Lexical, syntactic, and cohesive features found in the writing and speaking transcripts were examined as linguistic features. Results indicated that when controlling for vocabulary/grammar knowledge, higher-rated language use during both speaking/writing performance was predicted by higher type-token ratios, suggesting the importance of diverse lexical use across modalities. Differences between modalities were also reported, such that higher-rated language use during speaking was related to greater function-word types and overlap. This supports the importance of using function words that help build links among entities during speaking. Higher-rated language use in writing was related to words that are less accurately responded during word naming tasks, indicating the importance of using more sophisticated words in writing. Syntactically, higher-rated language use during speaking was related to greater noun-phrase variety, while higher-rated language use during writing was related to greater noun-phrase complexity. Lastly, results indicated that linguistic knowledge is a source of the common variance between speaking and writing. Overall, findings provide speaking-writing similarities and distinctions in language use.
