When zoro will be with robin?
Eiichiro Oda, the creator of One Piece, has specifically said that there will be no romance in One Piece and so there will be no couples. Therefore, Zoro and Robin will never "get together".
If you've noticed, no crew member actually expresses any romantic feelings towards each other, except for Sanji, who acts on lust alone and will do so for any pretty face regardless of personality.
None of the crew are in a strong relationship because Oda thought that romance would slow down the series. He quoted "They're in love with adventure" so they want to get it going with the excitement and upbringing. If there were to be romance until the end of the show, Zoro would possibly go with either Robin or Talingui(?) Altough there have been many fanarts of ZoroxNami, Zoro just sees Nami as a friend.
Well, it's a long story, but pretty much this sums it up: Zoro was on a journey (to become the best swordsman in the world) When he arrived, a girl, Rika, was attacked by Helmeppo's, the spoiled son of the corrupted Marine captain Axe-Hand Morgan, pet wolf. Zoro saved her by killing the wolf Zoro was arrested and Helmeppo made a deal with him: if Zoro could survive a month without food, he would be…
In One Piece did Kaku feel sad after he was defeated by Zoro like he enjoyed working for Galley La Company?
Why is Sanji from One Piece described to be the second son of a family when he actually is older than Zoro?
Zoro and Sanji are actually the same age. I'm pretty sure he's described as the second son because Zoro is much more watchful and protective of all of the crew, very much like an eldest brother, and everyone relies on him. It may also be because he was the first to join Luffy. That's just how Oda described them though...
Kuina died and Zoro asked for her sword. at the time, Zoro was already using the two-sword style, and in asking for Kuina's sword he had asked to carry her wish on along with his. in the sense that he couldn't give up his determination to make room for hers, he couldn't give up one of his sword for hers either. so he just added a third sword - the three-sword-style!! :D