As fair as I'm aware and have read in grammar dictionaries, ~ようかな can take
both meanings of "I wonder if I should...." and "I guess I'll....". Obviously,
there is a big difference between the two as the former is simply pondering a
possibility and the latter is making a direct volitional statement with a bit
of uncertainty. I wouldn't want to convey the wrong message.

How are these distinguished?
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2020-04-30T00:02:07.413
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question
nuances
Meaning of ~ようかな between "I wonder if I should...." and "I guess I'll...."