Oftentimes, vocabulary used for foods can be confusing, using different words to refer to the same thing i.e. soda and pop, EZ-Cheez and Easy-Cheese, Quesadillas and tortilla melts
This is confusing for non-native speakers who assume that everything only has a single word, which is the case for the Japanese word o-cha, which refers to both Japanese tea and green tea. So, how can you teach a student when each word is appropriate?
Drill the student on their nationality by using the grammar pattern of “Which nationality are you?”, to encourage the student to say “I am Japanese”. Expand on the grammar practice by asking “Which nationality is your tea?”, to which they should respond “It is Japanese” or “My tea is Japanese”. With both the student and the tea’s nationality established, the student will understand that they drink Japanese tea.
The student will quickly understand that green tea and Japanese tea are one in the same, and will have no problem using either term to describe the bitter deliciousness of Japanese お茶 (o-cha).
Yes, green tea is the most produced tea in Japan, and when people say お茶 they are referring to it. Another more appropriate term might be 日本茶.
Keep in mind, however, that other countries such as China also make green tea, and Japan makes black tea as well.