I am a native speaker from California, USA, and can help you learn not only American English, but I can also help with British(/international) English as well.
I have worked correcting formal written English and know almost everything about "correct" grammar, but am also up on slang and casual speech, especially hip-hop, listening to rap since 1985 (old school!)
I will text or voice chat (e.g. Skype) for 10 minutes, or correct a text up to 100 words.
Además se habla español.