I am having trouble with the term "kai". According to wiktionary, "kai" means 'probably' or 'maybe, perhaps'. Why do we continuously translate "kai" to "I guess"?
Probably idiomatic usage. This is what my dictionary says:
kai probably, presumably; (ehkä) maybe, perhaps; kyllä kai I guess [so]; ei kai hän kauan viivy I don't think he'll stay long; pitää kai lähteä I suppose we must go
Although kai per se is impersonal, it seems to reflect the speakers perspective. It is "ei kai", i.e. 3rd person sgl, but still translates as "I don't think". The last example is really weird since there is no subject at all, and where does "we" come from? Purely based on an assumed likely context? Would "Pitää lähteä" work as well?