A college student of intermediate to advanced English as a second language (ESL) is still constantly trying to identify the rules governing the language and making and correcting mistakes. Sociolinguistic theory can help to understand this type of active, advanced learner and the instructional strategies that complement this learning style. Four models of second language acquisition characterize ESL students and can lead to decisions regarding classroom strategies: the Acculturation Model, Accommodation Theory, the Interlanguage Hypothesis, and the Monitor Model. From these theories, educators can see the significance of underlying psychological factors that influence second language learning. College writing teachers in particular, because of the critical learning stage of their students, must be aware of psychological factors and attempt to identify students' attitudes and motivations. These factors include the social and academic context and self-consciousness about accent. Teaching techniques should reflect a natural, informal environment conducive to interaction. Although contrastive analysis is inappropriate in many cases, it can be used with college ESL writers to understand errors and demonstrate what works and what does not. A rich, supportive linguistic environment is vital to the long-term developmental writing process of ESL students. (MSE)