The present paper is a review of literature in relation to formulaic sequences and the implications for second language learning. The formulaic sequence is a significant part of our language, and plays an essential role in both first and second language learning. The paper first introduces the definition, classifications, and major features of formulaic sequences. Then relevant studies on second language learning are reviewed, and pedagogical implications will be drawn from previous research. It is suggested that more emphasis should be put on prefabs in foreign language teaching, but at the same time, there is also danger of overemphasizing the role of prefabs in SLA research, given limited exposure to the target language in a foreign language learning environment.