This statement is so absolute that it hides (seems to dismiss) the fact that both -τός and -τέος types may in some circumstances retain / allow / require some elements of the syntactic constructions typical to the verbs from which they are derived. Those two types function in different ways syntactically, but the statement "regular adjective syntactically" was too simplistic, because it was only considering the relationships between an adjective and it nominal. In the broader context of a phrase there are other things to consider - namely the way a verb (typically in its passive syntactical constructions in this case works together with other elements to create meanings). Adjectival syntax at that level is interesting to observe, but a few steps above my pay-grade to be able to manage yet.Stephen Hughes wrote:the -τός seems to be derived from the verb and functioning as a regular adjective syntactically. The -τέος, meanwhile, functions as a verbal form within its own syntactic patterns.
Many of the -τός type verbal adjectives are from verbs, which do not occur in the New Testament, or not in the New Testament in the sense (issue of polysemy) that the verb from which they are derived from does.
This doesn't add that much to this discussion, but I thought I should clarify that.