"I really appreciate that you taught me such enjoyable ways to learn English. Although I wasn't a very diligent student, I still learned a lot of new words and phrases. After 15 months of learning, I have found myself not being too shy talking to a native speaker. You have proved learning English after a certain age is possible. I am sure you'll encourage many more students of yours in Japan. I wish you the best of luck!!"
Good morning, Masa. How are you? I'm fine. How about you, Chris?
という具合です。英語での決まり文句で「How are you? 」と続きます。「元気？」とか「儲かりまっか？」ぐらいの軽い挨拶です。特に問題がなければ「I'm fine」という普通の返事で済みます。その後に今度は相手の様子を尋ねます。もし徹夜明けで眠ければ「I am sleepy because I worked overnight」と答えてもいいです。