New Defender's Study Bible Notes
12:2 when I called you. Jephthah’s reply indicates that, perhaps even before he had been called to fight the Ammonites, the elders of Gilead had indeed requested help from their sister tribe of Ephraim, and had been either refused or ignored.
12:4 fugitives of Ephraim. Their taunt of the Gileadites by Ephraim, perhaps based on the long-before request of the two-and-one-half tribes for the lands east of the Jordan, was the trigger that precipitated this unfortunate inter-tribal warfare.
12:6 pronounce it right. Three hundred years in their separate provinces in Canaan could make a significant difference in local pronunciations, even between two tribes of Israelites (compare differences between Brooklyn and Birmingham accents today!).