The contributions of teachers in building foundation of social processes, promoting learners’ agency and engagements have been constantly highlighted. This study explores language socialization of English Language Learners (ELLs) in an elementary school in U.S., focusing on the role of an ESL teacher. It examines how the ESL teacher provides linguistic and cultural scaffolding, and creates a learning environment conducive to ELLs’ socialization into American school academic discourse (Gee, 1999). A prevalent approach for linguistic scaffolding was through using questions. Questions were used for assessment, identifying prior knowledge, current understanding level, and potential level for future development, and to train ELLs to think critically and analytically. Cultural scaffolding was made through classroom scripts, such as whole group and small group activities, individual work with teacher assistance, and working locations in the classrooms. The classroom script projected American values of power functioning, respect for individuals, and freedom of choice. The findings imply that ESL learners need more than linguistic scaffolding and having the knowledge of cultural learning dynamics could be crucial in multicultural students’ socialization into the mainstream American school discourse.