Twenty words and not one finite verb. The whole passage is a chain of infinitives with imperatival force: διδάσκειν, δεικνύναι, αἰτιᾶσθαι. Neither "you must" nor "do" — just the bare instruction, like a noted-down procedure. It is the most compressed prescription in the corpus for dealing with another's error, and it rests on three steps, each of which retreats one pace.

Step one: teach. σφάλλεται — "he stumbles, goes wrong," not ἁμαρτάνει. Marcus picks the milder word: not an offence and not a sin, but a misstep in walking. The vocabulary already withholds condemnation, and so the only fitting response is DOGMAδιδάσκειν εὐμενῶς, "to teach kindly". The adverb εὐμενῶς carries the whole weight: not to correct, but to correct benevolently. Cf. 9.11 ("correct by teaching if you can") and 6.27.

What exactly is to be shown. τὸ παρορώμενον δεικνύναι — "show what is being overlooked." παρορώμενον from παροράω, "to look past": the error is understood as a defect of seeing, not of will. Hence the verb of response is δεικνύναι, "to show" — not to prove, expose, or punish. The entire treatment consists in turning another's gaze toward what it failed to look at (cf. 9.42: everyone who errs "misses the mark set before him" and can therefore be re-taught).

Steps two and three: the release of blame. εἰ δὲ ἀδυνατεῖς — "but if you are unable." Not "if he will not listen," but precisely "if you have not the power": the failure is referred to oneself, not to the other's obstinacy. And then the most unexpected move in the passage: σεαυτὸν αἰτιᾶσθαι ἢ μηδὲ σεαυτόν, "blame yourself — or do not blame even yourself." Marcus carries the transfer of blame all the way and cancels it in the same breath. If you did what you could, there is no residue of blame anywhere: not on him, not on you. This is neither self-flagellation nor indifference, but the clearing of the field of the very category of the culpable. The governing discipline is action, the sustaining one assent.