The English articles, the, indefinite a/an, and zero can often be troublesome for English language learners to master, especially in longer texts. Thomas (1989) demonstrated that English as a second language (L2) learners from first languages (L1) that do not have the equivalent of an article system encounter more problems using articles. Ionin and Wexler (2004) found that such learners fluctuate between the semantic parameters of definiteness and specificity. This study examines English L2 article use with Taiwanese English learners to determine the potential factors influencing English article substitution and error patterns in their academic writing. This corpus-based analysis used natural data collected for the Academic Writing Textual Analysis (AWTA) corpus. A detailed online tagging system was constructed to examine article use, covering the semantic (specific and hearer knowledge) as well as the other features of the English article. The results indicated that learners overused both the definite and indefinite articles but underused the
zero article. The definite article was substituted for the indefinite article in specific environments. Although no significant difference existed between specific and non-specific semantic environments in zero article errors, a significant difference emerged between plural and mass/non-count nouns. These results suggest that, in regard to writing, learners need to focus on the semantic/pragmatic relationships of
specificity and hearer (or reader) knowledge.