In some cases, the decision is easy - the school has a clear policy to be followed whether Japanese can be used or not. In other cases, it is up to the native teacher, and even in cases where there is a policy, it may not be able to be applied to each class perfectly. Let’s look at some of the pros and cons of using Japanese in the classroom.
Pros: The pro side is that students understand more quickly, and can be more enthusiastic, when presented with a topic in their native language. Low-level students can become easily discouraged, so translating can keep them involved in the class. Lessons can move along more quickly and with less disruption.
Cons: The biggest cons are that speaking Japanese in the classroom limits student’s exposure to English, and prevents them from developing listening and thinking skills. If students are just waiting for a Japanese translation, they have no motivation to listen to the English instruction.
Using Japanese in the classroom also prevents students from developing strategies to cope when they don’t understand something, be it checking a dictionary, using critical thinking skills, or consulting with peers. Students may pick up some vocabulary, but not real English skills.
Many teachers find that they can communicate with students just as well using a combination of English, gestures, pictures, and examples, thus eliminating any need to use Japanese.
To this end, some teachers try and pretend, or don’t have to pretend, that they don’t speak any Japanese at all in order to encourage students to use all the English they can. Other teachers think that this strategy can backfire, especially when solo teaching, because students without a wide vocabulary will not feel comfortable asking questions.
Obviously the goal of any communication class is to increase students ability to use and communicate in the target language. While we can aim for 100% immersion, sometimes using a bit of the native language for support can get more results from the class. The teacher must decide for him or herself what the best approach is.
Be mindful that English input time is precious. Your students hear Japanese all day, all week, all the time. You should always be doing as much as possible to maximise their exposure to English.