One of the most common grammatical errors native speakers of English do seems to be (I) use to (do) for (I) used to (do).
This one I saw for the first time (Youtube comment): Emma https://www.youtube.com/channel/UCFVrdMtKnvpBQ69kdjpYbRw1 päivä sitten https://www.youtube.com/watch?v=uDQtTfAn5hk&lc=z13xxn3ymtqef5vji04cgv3jiou4i15oepc0k the least howie could of done was clapped for her... Seems to me that's her idiosyncratic phrase. At least I hope so...
