This study examines the effects of the continuation task and the model-as-feedback writing task (MAFW) on English as a foreign language (EFL) vocabulary learning. Three classes of intermediate-level Chinese EFL learners were randomly assigned to a continuation group, a MAFW group, and a control group. Three aspects of vocabulary knowledge -- written form, meaning and form, and grammatical functions -- were each assessed by receptive and productive tests. It was found that (1) both tasks led to significant immediate and long-term development of word knowledge of written form, form and meaning, and grammatical functions; and (2) the continuation task showed superiority over the MAFW task in enhancing productive knowledge of written form, and receptive and productive knowledge of form and meaning as well as grammatical functions. Implications of these results for EFL vocabulary teaching are discussed.