This distinction is a bit tricky. When birth is being discussed, the past participle of “bear” is usually “born”: “I was born in a trailer—but it was an Airstream.” Note that the form used here is passive: you are the one somebody else—your mother—bore. But if the form is active, you need an “E” on the end, as in “Midnight has borne another litter of kittens in Dad’s old fishing hat” (Midnight did the bearing).
But in other meanings not having to do with birth, “borne” is always the past participle of “bear”: “My brother’s constant teasing about my green hair was more than could be borne.”
The simple past tense of “bear” when no helping verb is involved is of course “bore”: “Yesterday my wife bore twins.”
The dialectical form “borned” is not standard English.
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