The lexical clone construction in English - a.k.a. the double (Dray 1987), contrastive focus reduplication (Ghomeshi et al. 2004), or identical constituent compounding (Hohenhaus 2004) - involves the full reduplication of a lexical item or phrase to form a modifier-head construction with focal stress on the first (modifying) element. Recent examples include “Saying slavery was the cause of secession isn’t politically correct, it’s CORRECT correct” (Larry Wilmore on “The Daily Show”, 9 Dec. 2010), “She’s not a DOCTOR doctor, more of a dead person doctor, but a doctor nonetheless” (Dr. Brennan on TV show “Bones”, 9 Sept. 2014), “Do you love it? Or do you LOVE it love it?” (2007 Cold Stone Creamery ice cream commercial), “You mean ‘HERE here’? Or here more generally” (from Meg Wolitzer’s 2013 novel The Interestings). While varying across categories (adjective, noun, VP, adverb) and illocutionary force (affirmation, negation, question), these cases all illustrate the prototype use of clones on which I will focus; elsewhere, clones can also be used for scalar strengthening as in TALL tall or DEAD dead. Clones typically function as pragmatic slack regulators (Lasersohn 1999), inducing a partition of the relevant set and picking out the subset corresponding to what (given the context and/or common ground) count as core, salient, or literal category members. This study surveys the semantic and pragmatic motivations for - and effects of - cloning, addressing the role played by discourse priming (the tendency for an XX clone to be triggered by an earlier occurrence of X), the relation of cloning to lexicalization and compounding, the role of discourse and grammatical context in coercing a given interpretation, the role of prosodic focus, and the sociolinguistic variables influencing which groups of speakers are (or are perceived to be) more likely to use clones and when. I also touch on the relationship of cloning to non-reduplicated focus contrasts (e.g. “It’s not hot, it’s HOT”; “Was it a kiss or a KISS?”) and related constructions cross-linguistically.