Louw and Nida (*Greek-English Lexicon of the New Testament*) 89.87-88,
89.92-95, suggest that TE and KAI cover much the same semantic ground. KAI is
much more common, and is used with greater variety, than TE. Both can be used
sequentially (as can DE), and both can be used coordinatively (is that a
word?), but KAI can also be used non-coordinatively ("indeed," "even").
Grace and peace,
Perry L. Stepp, Baylor University