Translation of Ureinwohner

I want to work on the country specific terms first, then do a revision of the words that we have entered so far... please give me a few days to finish it. However, I may need to contact you over the weekend, depending on my progress.
Take your time to answer me, do the vocabulary exercises and measure your progress! Your answers will be kept in the system itself. After that you can look at the statistics. That's pretty cool here.
What is the past tense of 'to swim'? So either you say, I was swimming or yesterday I was swimming. Or: I was running yesterday vs. yesterday, I ran. You know the answer? I have no clue.