could table suggests
it is a nice day. we could go for a walk. Today the weather is good, we can go for a walk
shall for the first person in questions to the table to seek other recommendations
shall i open the window? = would you like me to open the window?
May (the Just) Well AS / Might (the Just) AS Well
"would be better", "might"
should / ought to table recommendations, advice
tone when the ratio should table recommendations could be much weaker, but to provide a reference for the hearer, the hearer can have a variety of options. And it is a hearer should be the best use of this option.
A:i need to get to the airport.
B1:you should take the airport bus,it's cheaper than a taxi.
B2:well,you could take the airport bus.or you could take a taxi.maybe clint could take you. he has a car.
He had better represent advice, implied "If they do not, there will be bad consequences."