In part 5 of Plato’s Meno, Meno is still trying to find out whether virtue can be taught or not. Many times throughout part 5, Meno thinks he has found the solution to his problem, but when  Socrates keeps questioning him he realizes that he has not found the solution yet.

So our first duty is to look to ourselves, and try to find somebody
who will have some means or other of making us better. I say this with special reference to
our recent inquiry, in which I see that we absurdly failed to note that it is not only through
the guidance of knowledge that human conduct is right and good; and it is probably owing
to this that we fail to perceive by what means good men can be produced.

p. 41

In this passage I think that Socrates was telling Meno that we always have to try to find someone who has a way of making us better. Socrates also says that knowledge is not the only way that people act right and good. They still do not perceive how good men can be produced.

From Socrates telling him this, Meno comes up with the conclusion that if people do not understand what virtue is, virtue cannot be taught.