Hi, I have a question please
I never see "so" used in writting.
The similar words like therefore, hence, thus, seem too formal.
Is there a word not as colloquial as so but not as formal as the others?
It not a matter of formality (though we more often say 'so' than 'hence'); it is primarily that 'so' should not usually be used to start a sentence.
Thank you for the clarification.
Noted down.