I'm a teacher but am having problems explaining some of the differences in modal meaning.
A pupil who has just returned from England said, " I could visit Cambridge, the British Museum and Rugby". My gut reaction is that she should have used "I was able to", but please can someone explain why.
Trust your gut.
'could' is used to indicate possibility : they could be right | I would go if I could afford it.
• used in making polite requests : could I use the phone?
• used in making suggestions : you could always phone him.
• used to indicate annoyance because of something that has not been done : they could have told me!
• used to indicate a strong inclination to do something : he irritates me so much that I could scream.
" I could visit Cambridge, the British Museum and Rugby"
This, and 'I go to...', sounds so American! 'While I was there, I could visit...' where 'could' is used instead of 'I was able to/had the opportunity to'
The sentence as it stands means to me, 'if I go to England I could...'
'I'll be free to get about with the hire car, so I could...
The person is in England, and is tossing up ideas for sightseeing: 'I could go to Rugby and see Cambridge on the way back, or...'