Can = poder, saber hacer Cant / cannot = no poder, no saber hacer
Amazing Animals Humans are incredible. Olympic champions can run at 35 kilometres per hour and swim at 8 kilometres per hour. And humans can read, write and talk, too. Animals can´t read or write, but they can do some incredible things.
A dolphin can swim at 50 kilometres per hour. A cheetah can run at 100 kilometres per hour. A polar bear can swim 150 kilometres in one day. A cobra can kill when its only five minutes old. A raft spider can kill fish.
Can humans swim at 50 kilometres per hour? No, they cant.