。
Can she play the piano?
Literal
She [topic-は] piano [object-を] play [can-ことができる] [question-か]?
~ことができる ('can do, be able to do') uses こと to nominalize the verb, then asks whether that nominalized action 'is possible' — a slightly more formal alternative to the simpler potential form 弾ける. The polite ます-form here (できますか) signals a courteous, possibly third-person inquiry. Asking about someone's ability is one of those everyday small-talk routines that the language equips with both casual and formal options.