"I have a great Chinese teacher" 的英语表达是 "I have an excellent Chinese teacher" 。
"excellent" 是形容词，意思是 "非常好的，极好的"。
举例来说：
"My Chinese teacher is excellent. She is always patient and knowledgeable." (我的语文老师非常好。她总是耐心和知识渊博。)
"I have an excellent Chinese teacher. She has helped me to improve my Chinese skills." (我有一位极好的语文老师。她帮助我提高了我的汉语水平。)