What is the difference between these JuJitsu and Aikido technique names?

Question

I did JuJitsu and Aikido for several years, and four of the basic controlling techniques which are essentially the same, have slightly different names:

JuJitsu: Ikkajo, Nikajo, Sankajo, Yonkajo

Aikido: Ikkyo, nikyo, sankyo, yonkyo

What is the difference between these naming conventions?

Answer 1

Actually, "Ich", "Ni", "San", "Yon" and "Go" are Japanese sequential or ranking terms the equivalent of which are "First", "Second", "Third", "Fourth" and "Fifth" in English.  Am not sure about "Kajo" though I have encountered old Aikido manuals that used the "kajo" nomenclature before, but as someone above has posted, it is possibly an archaic Japanese term which evolved to "kyu" today, kinda like how the English word "Can not" evolved to "Can't". Anyone who speaks Japanese can correct me on this. But "Kyu" in my experience is a ranking designation below Dan or master grade. Think of it this way, the "Kyu" wazas are like grade school level lessons and the Dan(or Black belt rankings) are high school level lessons. So basically Ikkyu, Nikkyu, Sankyu, Yonkyu and Gokyu are literally translated as First grade technique, Second grade technique, Third grade technique and etc. referring to lessons or techniques on that grade or rank level. For the Dan rankings, the terms used are Shodan, Nidan, Sandan and so forth. As you can see, these terms are generic Japanese terms and therefore explains why it is used in other Japanese martial arts' teaching curriculum especially those that trace their origins from Aikijujitsu, to simplify the lessons and identify the different techniques in each system.

Answer 2

According to someone on Aikiweb it is dialectal.

"The -kajo suffix was used in "older" martial arts like Daito ryu aikijujutsu from which aikido stems."

It appears that depending on the lineage of aikido, some (like Yoshinkan) use the older terminology. They mean the same thing.