Χαίρετε!
Unit 27 of Dr. Mastronarde’s book on the top of page 229 states,
"A second use of the accusative absolute is with a noun and personal-verb participle
introduced by ὡς or ὥσπερ, as if, in the belief that:
ὑμᾶς ἐξαιτήσονται, ὡς ἐκεῖνον πολλῶν ἀγαθῶν ἀλλ’ οὐ πολλῶν κακῶν
αἴτιον γενόμενον.
They will beg you for a pardon, just as if that man had been responsible for
many good things and not for many evils."
What does the book mean by personal-verb?
I happen to be working on unit 27 right now.
Look at the previous section at the bottom of page 228.
There are three examples of participial clauses with the participle being an impersonal verb.
In the first example, the subject of the participle is an infinitive, not a person.
δέον πείθεσθαι
to obey being necessary
or
it being necessary to obey
πείθεσθαι is the subject of δέον
Now look at the top of page 229.
Here the subject of the participle is a person, not an infinitive.
ἐκεῖνον αἴτιον γενόμενον
that man having been responsible
ἐκεῖνον is the subject of γενόμενον
Εὐχαριστῶ!
For a while I was wondering if I was reading a grammatical term that I was not familiar with.
As a footnote I would say that the difference here is not that the “the subject of the participle is an infinitive” but more that the verb from which the participle is formed is an impersonal verb As M. says on p. 228 :
“the participle of the impersonal verb appears in its neuter singular form, and the substantive subject of the phrase is usually either an expressed or implied infinitive or a noun clause (rarely a neuter pronoun)”
On p. 229 M. then talks about “a noun and personal-verb participle”. In the example
“ὑμᾶς ἐξαιτήσονται, ὡς ἐκεῖνον πολλῶν ἀγαθῶν ἀλλ’ οὐ πολλῶν κακῶν αἴτιον γενόμενον.”
γίγνομαι is not an impersonal verb and so to make the distinction clear between the two uses of the accusative absolute he uses the term “personal-verb” to describe this second type. Generally speaking one only talks about “verbs” and a subset which are “impersonal verbs”.