What does ことが mean here?


犬は泳ぐことが出来ます。

A translation for this sentence would be 'The dog can swim', right? Is it
necessary to use ことが? And what does it mean?




こと here is a nominalizer, and it's necessary because ～ができる only takes a noun.
See [this question](https://japanese.stackexchange.com/q/29367/5010), too.
Literally, 泳ぐことができる is translated as "can do swimming" rather than "can swim".

泳ぐことができる and 泳げる both basically mean "can swim". But as you can easily guess,
the longer version is more explicit about the ability, and sounds a bit more
formal/technical. The former sounds closer to "have an ability to swim" rather
than simple "can swim."




こと here is a nominalizer, and it's necessary because ～ができる only takes a noun.
See [this question](https://japanese.stackexchange.com/q/29367/5010), too.
Literally, 泳ぐことができる is translated as "can do swimming" rather than "can swim".

泳ぐことができる and 泳げる both basically mean "can swim". But as you can easily guess,
the longer version is more explicit about the ability, and sounds a bit more
formal/technical. The former sounds closer to "have an ability to swim" rather
than simple "can swim."

