This article aims to uncover how L2 writing is affected by alignment, a socio-cognitive process involving dynamic coordination and adaptation. For this, two studies were conducted. Study 1 required two groups of 24 learners of English as a foreign language (EFL) to continue in English two stories with their endings removed, both of which had a Chinese version and an English version. Each group continued one story following the reading of its Chinese version and the other following the reading of its English version. Study 2 asked another two groups of 24 EFL learners to write, without an input text, on two topics meant to activate their contextual knowledge. One topic was related to an English film and the other to an L1-based anecdotal experience. Results showed that (i) alignment manifested itself in the continuation when the learners performed the English-version task, as they used more lexical items in the original story and thus committed significantly fewer errors in comparison with their performance on the Chinese-version task, and (ii) a task that activated the learners' L1 contextual knowledge incurred significantly more L1 transfer errors due to self-alignment.