Shwmae Dan. You’re not mishearing anything. The Welsh for ‘you came’ and ‘did you come?’ are exactly the same: ‘wnest ti ddod (?)’. It’s all about the intonation. If you say ‘you came’ in a questioning tone, it becomes ‘did you come?’. Hope that helps.
Yeah that does help. Thanks Jon, glad I asked.
(I also asked my partner who is welsh (and fluent in speaking welsh) and she didn’t know the answer haha)