Final answer:
Code-switching is when people speak different languages and can't understand some words that the teacher says. Research suggests that allowing students to use their authentic voices is beneficial for learning.
Step-by-step explanation:
Code-switching, or alternating between two or more languages or language forms, is a common phenomenon where people speak different languages and can't understand some words that the teacher says. This can happen due to differences in culture, family, and region. However, newer research suggests that allowing students to use their authentic voices, including nonstandard dialects, is more equitable and beneficial for learning.