This study examined the effectiveness of Zipfian frequency at facilitating the acquisition of English prenominal past participles. Chinese middle school students (N = 103) were randomly assigned to a sequenced Zipfian frequency (SZF) group, a random Zipfian frequency (RZF) group, a balanced frequency (BF) group, and a control group. A mixed experimental design was used to detect the development of the learners' prenominal past participles. An untimed acceptability judgment task and a timed grammaticality judgment task were employed to assess the learning effect triggered by different types of frequency. Results of the timed grammaticality judgment task indicated that SZF was as effective as RZF and BF for learners to learn the grammatical prenominal past participles but more effective than RZF and BF for them to unlearn the ungrammatical ones in the midtest. Results of the untimed acceptability judgment showed that SZF was not superior to RZF and BF when learners learned the grammatical prenominal past participles, but more beneficial for them to unlearn the ungrammatical ones than RZF and BF in the post- and delayed posttests. Pedagogical implications for second language construction teaching are discussed.