Mary, as you know, dialects obey no rules of the grammar. This is true also for the Savo dialect, even though I would not call it a dialect. It's a language in its own right, more a mother tongue than a dialect. You omitted something: HE in Savo is HYÖ. I still remember when a schoolmate of mine in early 1950's once said to a teacher: " But TYÖ said that..." The lady in question saw red: " I am not TYÖ, I'm TE".
There are still worse as far as Finnish geographical regions go. In Bothnia, MINÄ would be MÄÄ (yes, like a pack of sheep), SINÄ would be SÄÄ (no weather forecast involved) etc. In Carelia, MINÄ would be MIE, YOU would be SIE, and HÄN would be HÄÄ ( almost like wedding). How would you understand: "Ehä mie mittää mut häähähää!" Interpretations are many but one might, just might, to be "I am/have not done anything but he/she is/has".
Right. How about the US of A? "Ah dunno if you're from deepinharta Texas? Ain't got no goddamn law in these here parts? Gotcha, see ya!" Long live dialects, at least they tell you something of the people.