Student or Learner
The police try to find out what happened or what is the truth.
The police try to find out what happened or what the truth is.
Which is the correct sentence? Could you explain why?
It would, of course, be a lot simpler to say "The police tried to find out the truth and/or what actually happened".
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.