A simple way to sort out the so-called middle voice is this: it stands mid way between the active and the passive.The passive voice consists in those expressions with 'is/are (being) ...-ed' (or the like): 'he is (being) led' / they are led' (=somebody else is doing the leading) --> ἄγεται... ἄγονται.
The same endings serve (in present tense) for middle and passive.
So it may help to sort out the meaning of ‘middle verbs’ on a continuum from the passive.
(1) some are true passives (in origin): such are
πείθομαι I obey = I am persuaded; (< πείθω, persuade)
and φοβέομαι I fear = I am frightened (<φοβέω, frighten or cause fear)
(2) most verbs in Greek may have active and middle forms:
(a) these may have distinctive translations,
like λύω I release, and λύομαι, ransom
(b) but many just add a certain ‘self-referential force’ = do it for oneself, by oneself itself. These may be close in meaning to reflexive,
like λούομαι I wash (myself); ἐγείρομαι I get (myself) up.
(3) and then there are the ‘deponents’—with no corresponding active form
These are the most important group for this chapter (listed p. 78):
ἀφ-ικνέ-ο-μαι
βούλ-ο-μαι
γιγν-ο-μαι
δέχ-ο-μαι
ἔρχ-ο-μαι
Memorize this list and practice conjugating,
esp. he/we/they --> βούλεται, βουλόμεθα, βούλονται