How would be in Ukrainian He understands what to do?
Він розуміє що (треба) робити.
Thank you Sergiy!
Is the second він not redundant here?
It can be omitted.
Why have розуміє and робить so different endings? Are they both 3rd person present?
How would I say "He does what he understands."
Розуміти follows the 1st verb conjugation, and робити has the "ити" ending so it follows the 2nd verb conjugation, both verbs have different conjugations even though they're both 3rd person as you stated.
"Він робить те, що він розуміє"
Is the 'He' the same person or does it mean two different males?