② motivation
Motivation: the learner’s overall goal and orientation
Instrumental motivation: learner’s goal is functional （功能性学习动机）
Integrative motivation: learner’s goal is social （介入性学习动机）
③ acculturation （文化移入，文化适应）
It has some relation with integrative motivation, the extent to which learners differ in the process of adapting to the new culture of the L2 community. This adaptation process is called acculturation
The learning of a second language involves, and is dependent on, the acquisition of the culture of the target language community.
The acculturation hypothesis states simply that the more a person aspires to acculturate to the community of the target language, the further he or she will progress along the developmental continuum, but focuses not so much on the actual processing of the second language as on the social and psychological conditions under which L2 processing is most likely to take place successfully.
④ personality
Outgoing personality may contribute to language acquisition
Extrovertedßàintroverted
Research results lead only partial support to this hypothesis.
Oral fluency, not overall proficiency in a second language

In general, a good second language learner is, among other things, an adolescent who has a strong and well-defined motivation to learn, who is able to respond and adaptable to different learning situations, who seeks out all opportunities and makes maximum use of them to interact with the input, who employs appropriate learning strategies, and who is willing to identify himself or herself with the culture of the target language community.