Many Japanese have experiences to learn English in their school days and have talked with foreigners, not only educated gentleman or lady, but teenagers use English without hesitation. If you are willing to talk with Japanese, they will try to have a conversation with you frankly. If you want to try, you can visit bustling cities like Umeda in Osaka, especially on the holiday like Halloween. You may be spoken to by someone unknown.
This is a Japanese character, ”Foreigners are welcomed”.
So if you firstly try to be friend with Japanese, you don’t have to speak fluent Japanese, you only have to show your respect, and honesty. Then they will understand and welcome you. Why not starting with a brief greeting in Japanese?
[Greeting works in anyway]
Firstly, it’s enough to say brief Japanese greetings like “Ohayo Gozaimasu” or “Konnichiwa” just looking into the eyes. They will precisely imagine your Japanese skill with your accustomed manner or articulation. This is why you don’t have to tell your all learning outcomes. Japanese are much accustomed with this kind of nonverbal communication.
Some tourists are willing to bow or join their hands in prayer as a gratitude, this is not totally recommended, of course for the foreigners trying to live in Japan. If you do, Japanese also welcome you with tender smile, but they may feel it nonsense. Some informed people may feel uncomfortable. They well know that Japanese cultural reverse import causes misunderstanding on Orientalism. On the other hand, people who had learned English under the old educational system, may accept this behavior. (the above is just my point of view)
The point is I want you to have caring gesture as a native English speaker. Many of foreigners succeed in making Japanese friends by showing their humbleness.
[After you finished greeting, you can speak English]
But there may be a situation you will choose to speak in English, not in Japanese.
If you want to express in concrete terms, you should use your own languages. Especially at job places there is a case you have to tell concrete idea rather than making a frank atmosphere. For example, at the work place especially in Japanese service business, you have to enter the job place, with saying “Ohayo-gozaimasu” at any moment. And you have to go out the place with saying “Otsukare-sama-deshita” at any moments. This is a conventional phrase. I strongly recommend you to remember such a particular rule.