Verb conjugation of "schwindeln" in German

I hope you you had a successful week in Dortmund. Because of the bad weather at the last moment I could not get on my flight to Dusseldorf and I have stayed home. I was afraid to fly.
Please explain me the exact differences between British and American .... This year I'm trying to make the TOEFL. We can then discuss how we can prepare for this exam. I failed the first time.
Many thanks for your suggestions. They are very useful. I can't answer your mail now, but I will come back to you later when I'll have more time. I hope that you and your family are well!