請問,您是教哪一科系的指導老師? May I know which subject your work is teaching? 請問,您主要是從哪方面的記者? Great my English is not good enough so far to figure out the second one English sentence. Sigh!

plus, in regarding to the "谢谢你的修改", 修改 does not apply in this case, since I have just sent you a reminder. 改 sometimes involve real/complete actions with strong wills. You should have used 纠正 instead ：）

谢谢你的修改Alec!

"谢谢你们的帮助" is a typical error of using 你们, you only use it when people are standing in front of you, in addition, your question is open to anyone isn't it. Just replace it with "大家" cheers

Q: 你是教哪一门课的老师？（正式） 你是什么老师？（不正式） A: 我是英语老师。 ----------------------------------- Q: 你是报道哪个方面的记者？（正式） 你是什么记者？（不正式） A: 我是金融记者。