In Modern English, a new phoneme developed that did not exist in Middle English. The phoneme comes from three sources: the word "father" lengthening from to for an unknown reason (thus splitting from "gather"); the compensatory lengthening of the short in words like "calm", "palm", "psalm" when was lost in this environment; and the lengthening of before in words like "car", "card", "hard", "part", etc. In most dialects that developed the broad A class, words containing it joined this new phoneme as well. The new phoneme also became common in onomatopoeic words like "baa", "ah", "ha ha", as well as in foreign borrowed words like "spa",