Page 478 - Makino,Tsutusi.DictionaryOfIntermediateJGrammar

404 soko del
(The fur coat was on sale at fifty percent off. SO, I could
buy it.)

4. In "S1. Soko de, Sz," S2 cannot be a command, a request, a suggestion,
or an invitation, as in (4).
(4) %J8%EfPAQ,it;~/~-74 --flh~T8037x%- P75y:
< SA*$-F, *?ZT, &GI:& (Q~~%TY~L~/L~L;~L
?7I:L;tr'iT-F75'/ k'1;7L?L1$@A@). (Acceptable
form: {E+Ia% /TB+13%l &GI:&--)
(There is a party at Morita's tomorrow and many of our old
classmates are coming. So, {please join us by all means. I how
about joining us? I would you like to join us?})
(+ da kara in sore de (DBJG: 413-14))

Sore de and soko de are similar and are interchangeable in many situations.
Some examples follow.

In addition, like soko de, sore de cannot be used with a command, a request,
a suggestion, or an invitation. (See Note 4.)
Sore de, however, differs from soko de in several ways. First, sore de can
connect a cause and a result while soko de cannot, as in [2]. (See Note 1.)

[2] a. "f77773X~Tkf&Ed"&7f:, {?hT/*?ZT} $Z@W
fz < SA@W& (=(la))
(There was a big earthquake in San Francisco. Because of that,
many buildings collapsed.)
b. ~@&%L~S~I'X+-BI:< Sh.@kZSt~f:~ {?hT/*?ZTl
48 i2Bd5% < TW 3 1; kLGb1, (=(lb))
(I was forced to drink a lot of cheap whiskey last night. Because
of that, I have a headache and cannot get up today.)