Zoro used all three types of Haki in Pre Time Skip
∎ Observation Haki:
Note that Tashigi is obsessed with swords and yet failed to sense it. It requires something more than being "sword freak", otherwise also Tashigi should have been able to sense it.
It's only Observation Haki in his primordial stage, but he had it already.
∎ Armament Haki
This is kinda self explaining, Koshiro used the same words that Hyogoro told to Luffy
∎ Conqueror Haki
Conqueror Haki is the manifestation of spirit, as explained by Raylegh in chapter 597
And guess what Kaku said about Zoro's Ashura? Yes, he thought it was Zoro's spirit manifestation
∎ Observation Haki:
Note that Tashigi is obsessed with swords and yet failed to sense it. It requires something more than being "sword freak", otherwise also Tashigi should have been able to sense it.
It's only Observation Haki in his primordial stage, but he had it already.
∎ Armament Haki
This is kinda self explaining, Koshiro used the same words that Hyogoro told to Luffy
∎ Conqueror Haki
Conqueror Haki is the manifestation of spirit, as explained by Raylegh in chapter 597
And guess what Kaku said about Zoro's Ashura? Yes, he thought it was Zoro's spirit manifestation
CoA as in the ability to cut anything and nothing. Whereas CoO, as in able to locate his sword which is an inanimate object and when the boulders falling down Zoro was able to know where they would falls.