Abstract
A corpus-based study (Osborne, 2008) argues various kinds of syntactic
complexities induce errors in L2 writing; for example, the complexity of the subject
facilitates the omission of third person singular -s (TPS). Although this argument is
plausible, L2 learners do make mistakes in even rather simple sentences. We explored
potential causes of omitting TPS in English essays written by Japanese EFL
undergraduates using a keystroke logging system. Comparative statistical analyses were
performed between the contexts where TPS was correctly supplied and where it was
omitted, in both written products and writing process data. Three major findings are
reported. First, in written data, no statistical differences in complexity were found
between the two contexts. Second, the analyses of writing process data revealed that
typing the verb initial letter requires a significantly longer time in omissions. Third, the
coefficient of variation of production speed of TPS was higher than that of space key in
omissions. These findings imply that verb selection is cognitively demanding for learners,
and their insufficient verb knowledge may potentially cause them to fail at subject-verb
agreement. This phenomenon seems to clearly illustrate the relationship between
language processing demand and learners’ cognitive capacity.
