Many instances of ter- in Standard Malay of Malaysia have confusing active and passive forms (i.e., a construction such as [Noun TER-VP] can represent both active and passive functions). Two criteria, namely (a) substitution by a canonical passive marker, and (b) addition of the agentive phrase, are established in order to distinguish the passive and the active. Utilizing a modern corpus and a historical corpus, words comprised of passive terwere extracted and were then compared to the Malay canonical passive di- and the adversative passive kena. The results show that ter- appears less frequently than di- but more frequently than kena. Additionally, ter- is used informally in contexts related to personal daily life, typically denoting an unintended action. This study not only provides a criteria-based methodology to extract a particularmeaning from the multiple meanings of a grammatical morpheme, but also it discusses the grammaticalization process of these different functions of ter- utilizing corpora data. The results indicate that ter- develops from perfected to imperfected to stative forms in addition to other grammaticalization patterns such as from ability to possibility and from definite to superlative forms.