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