How Ottawa could get their 2019 first back

Why? They could just give up their 1st this year and then you don't lose White and a 3rd for what could be a 20+ 1st round pick.

Can they not just decide to give them the 4th overall this year and take the 2019 back...was that not the condition?

Assuming that Ottawa uses their 2018 1st pick and drafts 4th overall, I see absolutely no reason why Colorado would be so inclined to trade it back to Ottawa. As an unprotected pick, and considering the state of the Sens organization, there is an extremely good chance that the pick will be in the top 3. I'd suspect that pick is pretty untouchable, at least until the deadline to see where Ottawa is at in the standings.

To the person who made this post. The trade makes no sense. Ottawa currently holds both its #1 picks for 2018 and 2019, however, they have to give 1 of those to Colorado as part of the Duchene trade. Since it was a lottery protected pick, Ottawa can choose to either give Colorado this year's pick or next years. The only way they can get it back is to make a trade with Colorado for that pick. Something like Karlsson for the pick, then Ottawa has the 4th and likely the 1st overall next year.

However, if I'm Colorado, I'm going to be ruthless about that pick, cause Ottawa must know at this point, tough times are ahead. They'll be a terrible team next year and thats before Melnyk goes nuts cause his team is garbage. Duchene will want out, so will Stone and then they will have to go full rebuild. Colorado can just sit on the pick, it'll either be the 4th this year or if Ottawa keeps it this year then Colorado could have the #1 next year. The Duchene trade could go down as the worst ever in the NHL.