Wow! The difference is sooo slight that I don't even get it. Would you paraphrase his words or comment on this.So,and then can both be used to mean 'since that is so'. There is a slight difference. Then is most often used when one speaker replies to another:it means 'It follows from what you have said'. We do not normally use then when the same speaker wants to connect two ideas ('It follows from what I have said'). So can be used in both ways.
I've noticed that the latter example contains quotations that make 'then' semantically smoother. Right?It's more expensive to travel on Friday, so I'll leave on Thursday evening.![]()
It's more expensive to travel on Friday, then I'll leave on Thursday evening.![]()
'It's more expensive to travel on Friday.' 'Then/So I'll leave on Thursday evening.'