"I can play 'Die Fledermaus" on the
glockenspiel."
"I can't even say it."
What students need to know
We use "can" to talk about general abilities:
"I can drive a tank."
"She can sing the blues."
It also works for specific situations:
"I can make the 10 o'clock
meeting, but not the nine o'clock."
When referring to the past, we use "could":
"Remember old Duke? He could play
'She'll be coming round the mountain' with his eyes closed." But this only
goes for general abilities. For specific situations we need "was able
to": "I didn't get up in time for the nine o'clock meeting, but I was able to make the 10 o'clock."