When should I use a semicolon before a conjunctive adverb? It seems that sometimes a conjunctive adverb is used after a period. Consider the following example:
In these sentences, the conjunctive adverb may look like a coordinate conjunction (and, or, so, but, for), but it is not as strong as a coordinate conjunction. Therefore [emphasis mine], the semicolon is used to link the two main clauses, and the comma is used to set off the conjunctive adverb (really an one-word adverb cluster) from its main clause.
Look, they are taking about using a semicolon before conjunctive adverb, and they have use one right there without a semicolon! Or is that not an instance of a conjunctive adverb?