Sentence pattern 【Japanese grammar】verb dictionary form + ことができません (kotogadekimasen) = cannot + verb
On this page, you can learn Japanese grammar for expressing what you can't do.
ability
Sentence pattern 
Sentence pattern good at + noun:【noun + が上手です】
On this page, you can learn Japanese grammar for 'good at + noun'.
Sentence pattern 【Japanese grammar】verb dictionary form + ことができます (kotogadekimasu) = can + verb
Let's learn how to say those sentences in Japanese: I can play tennis. My older sister can play the guitar. My father can speak English. My mother can drive a car.
Sentence pattern good at + verb-ing:【verb dict. form + ことが上手です】
On this page, you can learn Japanese grammar for 'good at + verb-ing'.