As far as I know they don't have the same root. The Ya in "running" imply there is a Ya in the end of the root. The Alif imply a letter in the middle of the root.
جري ≠ جار
Also /jar/ in Arabic it's like /gar/ in Hebrew where the root is [gwr] and the meaning is living (in a house). Generally in the semetic languages you can find a lot of similar root that are different if you check the exact location of the consonants.....