Introduction

How come … is used in colloquial English to ask for the reason for some event or state of affairs. Duffield (2015: 61) notes that it differs from why in that how come is ‘a more colloquial expression’, noting that ‘It is hard to to imagine, for instance, a prosecuting barrister asking a defendant “How come you rang Jane Price on four separate occasions, Mr. Fox?”’ For speakers of standard varieties of English, how come seems to be acceptable when followed by a finite TP containing an overt subject (bold-printed below) – as in the following pop song lyrics:

Some speakers also allow the use of the complementiser that after how come, as in the following (internet-sourced) examples:

There are also speakers who allow (Interrogative Subject-Auxiliary) Inversion after how come, as in the examples below (3a being attributed to Diane Lillo-Martin in Ochi 2004, 3b, c being examples from a corpus cited by Kim & Kim 2011, and 3d being sourced from the internet by me):