How are you?
I'm very well. And you?
All of them are Chinese.
Hello. My name's David. I am Australian. I am a teacher at the Language Institute.
你好。我叫David。我是澳大利亚人。我是语言学院的老师。(this last sentence I am very not sure of.)
That isn't her little brother, it's her friend.
Do you know Doctor Ma?
and then in pinyin, this is what I have for "I don't drink coke, but I'd like a coffee"
Wô bù he(macron) kêlè, (but?) wô yào kafei. (I don't know what word one would use for 'but' here?)
and for "Teacher Chen is a foreign language teacher" I have
Chen lâoshi shì wàiyû lâoshi. (is the shì correct?)