ことができる・
Use ことができる after a verb, or ができる after an activity noun, to say that someone has the ability to do something or that circumstances make it possible.
Ability and situational possibility
The construction has two closely connected uses. It can describe a person's learned, physical, or practical ability, or it can say that rules, equipment, time, and other circumstances allow an action.
妹は水泳ができます。
My younger sister can swim.
Analyze水泳 is an activity noun, so it can be followed directly by ができる.
私は漢字を少し読むことができます。
I can read a little kanji.
AnalyzeThe object particle を stays with the verb inside the clause.
この図書館では、無料でインターネットを使うことができます。
At this library, you can use the internet for free.
AnalyzeThis describes what the library's facilities and rules make possible, rather than a personal skill.
Keep particles inside the verb clause
First build the ordinary verb clause, then add ことができる. Do not replace the particles already required by the verb. For example, an object still takes を, and a destination can still take に.
駅で自転車を借りることができます。
You can rent a bicycle at the station.
AnalyzeThe location particle で and object particle を remain unchanged.
Short answers
When the activity is already clear, the reply can omit it and use only a form of できる.
Compared with potential verbs
A potential verb often gives the same broad meaning in a shorter form and is especially frequent in conversation. Use ことができる when you want to state the activity explicitly or emphasize that circumstances, rules, or facilities make it possible.
More examples
父は料理ができます。
My father can cook.
Analyze田中さんは車の運転ができません。
Mr. Tanaka cannot drive.
Analyze子どものとき、自転車に乗ることができませんでした。
When I was a child, I couldn't ride a bicycle.
Analyzeこの店では、カードで払うことができます。
At this store, you can pay by card.
Analyze午後六時まで、この部屋を使うことができます。
You can use this room until six p.m.
Analyze一人でこの箱を運ぶことができますか。
Can you carry this box by yourself?
Analyze