Translation of festigen in German-English

On the other sites I work with every 3 to 6 months developers are called together to exchange experiences. Everybody is kept up to date and new projects are introduced. It is good for workflow.
I've been working on and off on the dictionary during the entire week, and I'll spend some more hours on it this coming weekend. Sometimes he would get a bit mixed up and use formal Castilian sometimes instead of informal.
I once had a lesson with a private teacher, but unfortunately she could not come regularly. She was always sick, then I have visited a school in Andalusia, which was worthless, since we talked only German.