~koto ga dekiru (can)

The structure ~ことができる literally means "the thing of [verb] can happen," which reveals a fundamental difference in how Japanese and English conceptualize ability. In English, we place the ability directly on the subject: "I can speak Japanese" frames the speaker as the active agent possessing the ability. Japanese, however, abstracts the action into a thing (こと = thing/matter) and says that this thing-to-be-done can occur. This seemingly small shift reflects a deeper linguistic mindset.

Why does Japanese work this way? The こと nominalizer transforms verbs into concrete objects. When you say 日本語を話すことができます, you're literally saying "the act of speaking Japanese—that is something that can happen (with me as the context)." This creates psychological distance from the ability itself; it's not "I have the ability," but rather "conditions allow the action to occur." This is why ことができる often sounds more objective and less self-assertive than the English "can."

For English speakers, this feels redundant: why nominalize the verb at all? But in Japanese, this grammaticalization reflects a preference for describing what is possible within a situation rather than what the person possesses. The alternative form ができる (directly attached to nouns like 運転 drive) shows the same logic—the driving-ability exists as a potential thing. Understanding this helps you grasp why Japanese doesn't usually say something like "I have the ability to speak" (能力がある) in everyday conversation; ことができる is the natural way to express potentiality as an outcome of conditions, not personal capacity.