By "main" I mean I can only list one ... no cheating ...so I need to be serious. n-tuples. Yes, that is it n-tuples especially in the concordance. Which is an esoteric way of saying Logos does not support finding repeated phrases or word pairings in the concordance - my primary use of an external concordance tool I used prior to the Logos implementation. And Logos does not support multi-part lexical units such as "bucket list" or "Monday morning quarterback" in its tools. I remember when Logos was actively curious on topics of visualization and linguistics ... now, I'm left begging for simple things like n-tuples.
