Try not to laugh at these crude excerpts. Here is a list of moments when Socrates mistakenly took for granted that his conversant understood what he was talking about, according to Plato. Whoops:
Socrates: Then is the just also pious? Or while the pious as a whole is just, is the just as a whole not pious, but part of it pious and part of it something else?
Euthyphro: I don’t follow what you’re saying Socrates.
From Republic III:
Socrates: This concludes our discussion of the content of stories. We should now, I think, investigate their style, for we’ll then have fully investigated both what should be said and how it should be said.
Adeimantus: I don’t understand what you mean.
From Republic II:
Socrates: Then do you think that our future guardian, besides being spirited, must also be by nature philosophical?
Glaucon: How do you mean? I don’t understand.
Socrates: It’s something else you see in dogs, and it makes you wonder at the animal.
Socrates: If we leave this place without having persuaded the city, are we treating some people badly – and those whom we should least of all treat in that way – or not? Are we standing by agreements that are just or not?
Crito: I can’t answer your question, Socrates, since I don’t understand it.
From Republic IV:
Socrates: But it seems to me that, in the case of all things that are related to something, those that are of a particular sort are related to a particular sort of thing, while those that are merely themselves are related to a thing that is merely itself.
Glaucon: I don’t understand.
From Republic I:
Socrates: And would you define the function of a horse or of anything else as that which one can do only with it or best with it?
Thrasymachus: I don’t understand.
From Republic V:
Socrates: But, as we say, the unexpected often occurs.
Socrates: With this in mind, we must provide the children with wings when they’re small, so that they can fly away and escape.
Glaucon: What do you mean?
Socrates: Does not the nature of each harmony depend on the way it has been harmonized?
Simmias: I do not understand.
From Republic II:
Socrates: Don’t you know that a true falsehood, if one may call it that, is hated by all gods and humans?
Adeimantus: What do you mean?
Socrates: I mean that no one is willing to tell falsehoods to the most important part of himself about the important things, but of all places he is most afraid to have falsehood there.
Adeimantus: I still don’t understand.
Translations by C.D.C. Reeve, D.J. Zeyl and G.M.A. Grube.