rozumět uses the dative case?
"je nechápe František"?
second position rule for 'je'
This needs to be updated in the tips and notes then, je isn't one of the pronouns italicized.
That is because it can also appear in a strong position, it is not a strict clitic. But not here, this word order is strange.
Thanks, you're the man Vlad
What exactly is a strong position?
A stressed position typically at the start or at the end of the sentence.
why nechápe, but not nechápou?
singular, not plural