An afterthought on let alone

• “The baby can’t sit up yet, let alone walk” shows the canonical use of let alone.
• “The baby can’t walk yet, let alone sit up” seems to be a deviant use of let alone.
• The deviant use is not very rare and does not mean some people just “get it wrong”.
• In this special use, the speaker represents the second conjunct as an afterthought.
• The two uses can be linked via a general pattern with bleached pragmatics.

We here revisit the let alone construction, which was first described in a 1980s paper that put Construction Grammar on the map. Our focus is on a seemingly aberrant use where the first conjunct does not entail the restored second conjunct, as in I don’t have ten children, let alone one. We argue that this use should not be considered as a highly exceptional speech error or as evidence that some speakers wrongly assume that the first proposition is the entailed one. First, a systematic examination of let alone examples extracted from the BNC and COCA shows that it is not exceedingly rare, as does a growing collection of authentic examples we have collected over the years. Second, it constitutes a usage type in its own right, whereby the first proposition has most contextual relevance and the second conjunct is represented by the speaker as an apophasis-like afterthought. There are transitional cases between the two types (canonical and afterthought), where both conjuncts have considerable relevance. For contemporary speakers, the afterthought use may require extraction of a general pattern with bleached semantics and pragmatics, possibly re-filled in with specific information.