I assume the "wedi" formation is the perfect tense only rather than a simple past. Can anyone confirm this?
I have never learned the names of the English tenses so I find discussions about tenses in other languages difficult, but, looking at the site http://www.dysgwyr.co.uk/Resources/Tenses I think you are correct. I think in Welsh "Did you wash the car" would be "Olchaist ti'r car?" This tense is covered further down the course.
Thanks for the quick response. My apologies for not clarifying what I meant by "perfect tense."