1) I can read and understand.
2) You can swim.
3) Boys can speak fluently.
4) Doughter can buy this T-short.
5) They can learn many languages.
6) Butterfly can fly.
7) Alice cann't do this exercise.
8) Ann can jump.
9) Fox can run very fast.
10) Gloria can write amazing poems.
Can-это не местоимение, а модальный глагол.