You find that an English language teacher is using freely mother tongue in the class. She is using _____ method.

The correct option is grammar-translation.

Here is a step-by-step explanation of why this is the correct method:

1. Understanding the Grammar-Translation Method:
The grammar-translation method is a traditional way of teaching foreign languages. One of its key features is the extensive and free use of the students' native language (mother tongue) to explain grammatical rules, translate texts, and define vocabulary. The primary focus is on learning grammar rules and translating sentences between the target language (English, in this case) and the mother tongue.

2. Comparing with Other Options:

• Structural oral situation: This method focuses on speech patterns and structures, usually introduced orally in meaningful situations, with limited or controlled use of the mother tongue.
• Direct method: This method strictly prohibits the use of the mother tongue. It emphasizes teaching the target language directly through demonstration, action, and context, using only the target language.
• Audio-lingual method: Based on behaviorist theory, this method focuses on habit formation through drills and dialogues. The target language is used almost exclusively in the classroom to prevent native-language interference.

3. Conclusion:
Since the teacher is described as using the mother tongue freely in class, the teaching methodology aligns perfectly with the grammar-translation method.