step one: sound correspondence

[tsukikage]

Is it sad that I can't even manage to make a sound correspondance chart? I mean, how do I figure out if the sounds I'm "corresponding" are in the same "phonetic slot", if that makes any sense? For example, is the vowel lengtening symbol (somewhat like ":") its own phoneme, or part of the vowel before it? MAR! *stabbity stab*
Worst part is, I can't answer the actual questions until I finish this chart.