These are new concepts to me and I will grapple with them for a while, and I need to do more reading before I know what I think. But construction grammar is a non-modular approach to grammar in which morphosyntax, sounds, and discourse functions are considered not separately but intertwined as (generalized) constructions, and that is obviously a good and accurate view and just as obviously a practically complext task for which lazy linguists long lacked a liking. Further, language structure is shaped by language use, and so "grammatical constructionalization" is the task of understanding how wordphrasesoundsequencespeechacts like "let us" undergo syntactosemantipragphonogical change (extension, "bleaching") and turn into "let's" (to take only one key and clear example from English). Just the foregrounded awareness that language change happens across linguistic levels not in a push-and-drag way but with all the weird aspects of a construction huddled together and nudging each other into the future--for another English example, consider "going to"-->"gonna"--is worth one's time. There is a whole garden here and this is really the merest intro and I understand it as yet only in its broadest particulars but I am ready and willing to learn more. ( )