Lexis, Writing & Contrastive Rhetoric

‘ never thought I would be able to write 35 pages about writing:=)  The more I think about the reasons why people make mistakes when they write in a foreign language, the more convinced I get that it is lexis rather than grammar that does the trick.  More than that, it is not about learning lexical items in isolation, you have to learn multi-word chunks, which could either be sequences of words or sequences of word groups that often occur in close proximity to or are adjacent to each other. Interestingly, while the former do have a name (collocations), the latter do not. Shall I invent a term?! How about proximate and adjacent collocation sets?