Your characters can be taught new abilities and new talents just as you would in real life. They don't learn something new overnight. They have to be taught by someone or learn them on their own. You are free to have your characters learn whatever you like just so long as the character learns them realistically. The best policy is to make sure you keep a log of events like these. Make sure you save anything that might be put into question so you have a record of your activities on the muck. This will prevent people from questioning what you can and can't do and will save you from potential headaches in the future.
For help with logging, please view How To Post Logs or ask a member of our staff.