I am unable to transfer .mkv files to Ipod Touch, so I want to know how to transfer these files.
You can email avi files to your iPod and open with free OPlayerHD Lite.
That app likely uses iTunes File Sharing so you can transfer them via iTunes.
Go to iTunes>Help>iTunes Help>Sync your iPod....>Sync You Device>Transfer Files and follow the instructions.
Retrieving data ...