ページ1:

Can vs Be able to
Contemporary English
In old English,
Cunnan (know)
→ can
eg) I can swim.
knowing how
to swim,
In Latin,
Habilis (in a position to do).
eg). I am able to swim.
eg). I can swim, but
→
be able to
Given situation,
I can swim.
I am not able to swim today,
because I have a cold.
have the
ability to
Swim.
It's not
possible
Given the
Situation

ページ2:

Can = possibility
L
eg). It can rain today.
I Can = permission
eg) You can eat all those pizzas.
Could = past tense]
eg). I could pass the exam.
Could
I
euphemism
eg). We could arrive at the station by ten.
It could rain tomorrow.
Tess
definitive