Negative transfer in language learning is defined as:

Negative transfer occurs when prior knowledge from a learner's first language interferes with the learning of a new language. This interference can manifest in various ways, such as incorrect grammar usage, pronunciation issues, or vocabulary mistakes that arise because the learner unconsciously applies rules or structures from their native language to the new language they are trying to acquire. For example, if a Spanish speaker uses Spanish sentence structure when speaking English, it may lead to confusion or errors, which illustrates the concept of negative transfer.

This definition is crucial for educators to understand as it can help identify the specific challenges a learner may face based on their linguistic background. Awareness of negative transfer allows educators to develop targeted strategies to mitigate its impact, facilitating a smoother language learning experience.