(By Hannah J. Haynie): "This question is focused on comparative constructions that have a dedicated marker for the standard of comparison that does not fall under the umbrella of the locational comparative (GB266) or surpass/exceed comparative (GB265). Note that a language may have multiple comparative constructions, including a non-locational, non-surpass/exceed comparative as well as constructions that are described by those features. ❡
Crucially, the dedicated marker in this construction must not elsewhere have a surpass/exceed meaning or a locational meaning. It may, however, have other functions (e.g. temporal adverb, conjunction, etc.). It is irrelevant whether this marker is phonologically free or not or whether it triggers agreement in case, noun class, etc. ❡
Historically, comparative constructions with dedicated markers (sometimes called ‘particle comparatives’) grammaticalize from constructions of conjoined clauses. An example of a particle comparative would be the Germanic languages, such as English than. Note that any marking of the property word is not relevant here (e.g. English tall-er)."