Verb conjugation of "revise" in English

As I have already mentioned in my last email, it is a breakthrough, I have never been so successful. I have visited several Spanish schools and would like to discuss that by telephone with you.
The conjugations of verbs are the biggest problem for me. I have never studied Spanish in school, but visited evening classes instead. This year I want to take a full Spanish course.
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.