CAN/ CAN'T and COULD/COULDN'T FOR GENERAL TRUTHS

You may practice more with these concepts with the following exercises:

https://www.engblocks.com/grammar/exercises/modal-verbs/can-cant-could-couldnt/

https://www.perfect-english-grammar.com/modal-verbs-of-ability-exercise-1.html

https://www.englishexercises.org/makeagame/viewgame.asp?id=12869

https://wordwall.net/es/resource/17710787/english/could-couldnt-can-cant

https://wordwall.net/es/resource/3652297/can-or-could