Nobody answered your question, so let me give it a shot. First off, I think Mounce answers your question:
Mounce wrote:18.11 Deponent Verb. This is a verb that is middle or passive in form but active in meaning. Its form is always middle or passive, but its meaning is always active. It can never have a passive meaning. I will discuss the middle voice below.
You can tell if a verb is deponent by its lexical form. Deponent verbs are always listed in the vocabulary sections with passive endings. In other words, if the lexical form ends in an omega, it is not deponent (e.g., ἀγαπάω). If the lexical form ends in -ομαι, the verb is deponent (e.g., ἔρχομαι) You will have to remember that the word is a deponent.
οὐκ οἴδατε ποίᾳ ἡμέρᾳ ὁ κύριος ὑμῶν ἔρχεται (Matt 24:42).
You do not know on what day your Lord is coming.
Mounce, W. D. (2009). Basics of Biblical Greek: Grammar. (V. D. Verbrugge, Ed.) (Third Edition, p. 152). Grand Rapids, MI: Zondervan.
Really, you have to understand what this particular verb means in the middle voice, in this particular context, and that involves interpretation and perhaps a lexicon.
He also offers this warning:
Mounce wrote:There is some interesting research currently happening that questions whether there actually is such a thing as deponency. For example, many deponent verbs are intransitive (36.10) and therefore cannot be passive. See the class website for an ongoing discussion.
These days, most people here on B-Greek don't talk about deponents. Carl Conrad and others have convinced us that verbs are never deponent ("broken"), the old linguistic description was broken. This may be a bit much for a beginner who is working out of Mounce, but if you want to understand how most of us see it, see this:
https://agntproject.net/anlex/analytica ... -deponency
Or this:
https://agntproject.net/anlex/analytica ... -deponency
ἐξίσταντο δὲ πάντες καὶ διηποροῦντο, ἄλλος πρὸς ἄλλον λέγοντες, τί θέλει τοῦτο εἶναι;
http://jonathanrobie.biblicalhumanities.org/