Sungshim Hong and Jaekeun Lee. 2017. Let’s Talk about Let+Us: English Hortative and Causative Constructions. Studies in Modern Grammar 96, 67-88. This paper deals with the two seemingly alike constructions in the English language, LET’S construction and LET+US construction. The foci of the current research include (i) whether or not LET’S is a mere phonological contraction of LET+US, (ii) how they are different in their distribution, as well as their interactions with negation/Tag questions, and (iii) why they are different; their asymmetries are attributed to the internal structures of the two. That is, in this paper, their internal structures are distinctively proposed within the Minimalist syntax (Chomsky 1995, 2004, 2005, 2007). On the basis of a garden variety of the already known asymmetries between the two (Seppänen 1977, Fries 1964, Davies 1986, Palmer 1988, Potsdam 1998, Huddleston and Pullum 2002, Quirk et al 1972, 1985), we support the idea that in spite of some of their superficial similarities and looks, the two constructions, both of which contain an identical lexeme LET, need to be analyzed independently from each other. Following the insight of Alcazar and Saltarelli (2014), the light verb, v, is poised for Hortative LET’S in a mono-clausal configuration. The occurrence of Causative LET+US may contract into the isomorphic LET’S, the Hortative LET’S as well. Nonetheless, the Causative LET+US occurs in a bi-clausal configuration with a Tdef intervening, whose Spec is US or any other DP. This paper presents the internal structures of the Hortatives and Causatives differently so that their morpho-syntactic, semantic, and pragmatic disparities can be easily accounted for. It is suggested that the Hortative LET’S underwent syncretism (Radford 2004, Gelderen 2004, 2008), whereas the lexical LET survives as a main verb.

1. Introduction
 2. Previous Researchers on LET’S and LET+US
  2.1. LET’S as a Contracted Form of LET+US
  2.2. LET’S as an independent lexical unit
  2.3. Potsdam (1998): Inflectional Head Analysis
  2.4. Alcazar and Saltarelli’s Light Performative Hypothesis
  2.5. Interim summary
 3. Structures: LET’S vs. LET+US Constructions
  3.1. Mono-Clausal for Hortative LET’S
  3.2. Causative LET+US C-Selects TP
  3.3. Ramifications and Further Issues
 4. Conclusion
 References

• Sungshim Hong(Chungnam National University)
• Jaekeun Lee(Chungnam National University)