Why; why is it; for what reason or purpose?(adverb)
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Use "how come" in a sentence
"Which is how come Nick found himself sitting in Celtic Warrior in Nishi Azabu on a Thursday night, alone at the bar, nursing a bourbon and water and a headache, trying to maintain his sanity as a bad multiracial goth band played heavily Japanese-influenced Celtic war melodies, an assault on the ears almost too intense to be described, much less endured."
"“So how come you and Sin hate each other?” she asked as Alan turned the car left at Alphington Junction."
"And if he was, how come Joyful Turner was prepared to let him captain a fine sloop like Lisbetta?"