Преподаватель русского языка?

[drevo-obezyani.livejournal.com]

I have two questions about the phrase "я преподаватель русского языка" -

1) What is преподаватель? I know "преподавать" is "to teach" but i'm not familiar with this form of the word - it seems to me it should be "преподаю" or "преподавала."

2) Why is русского языка in genitive rather than accusative case?

Comments

[wire-shock.livejournal.com]

In this case it's definitely teacher, not a lecturer :-)