Psychological preparation

[Xinfu]

Are my sentences idiomatic when I have to say this to my friend who will be living in the same room as I in the coming term?

-I know you are learning Danish this term, but since I stayed in Denmark for only a short time, I can't help you in any way. I just mention/mentioned this to give you a psychological preparation. (=so that he will know he has to seek help from other people if he has to ask questions about the Danish language.)

[Cloudgazer]

-I know you are learning Danish this term, but since I stayed in Denmark for only a short time, I can't help you in any way. I only mention this to prepare you./I only mention this so you know what to expect.

[Xinfu]

Thank you.