Soumatome 20 Lessons JLPT N4 Grammar Lesson 13: V-dic + ことができます & Potential form

Use the potential form to say that someone has the ability or skill to perform an action.

The potential form also expresses whether an action is possible or impossible because of circumstances, conditions, or rules.

Pattern: (V dictionary form) こと / N + ができます
Note: A directly used noun is often a verbal noun such as 見学けんがく or 練習れんしゅう, or a noun that inherently includes an action, such as 外国語がいこくご, スポーツ, or 楽器がっき.

Group 1: 会う → 会える、書く → 書ける、立つ → 立てる、飛ぶ → 飛べる
Group 2: 食べ + られる → 食べられる
Group 3: 来る → 来られる、する → できる

When a transitive verb changes to the potential form, the object is commonly marked by 「が」 instead of 「を」.

This pattern has essentially the same meaning as the potential verb form.
The potential verb form is used more often in conversation.
When a sentence contains several following clauses and the verb is not simply in its basic form, 「ことができます」 is often easier to combine with the structure.

Verbs that already contain a meaning of ability or perception, such as 「わかる」「聞こえる」「見える」, do not need to be changed into the potential form.

An inanimate subject does not automatically rule out the potential form. In these examples, the intended meaning is that the thing is not actually functioning well, so the plain intransitive forms 「流れません／動きません」 are appropriate; 「流れられません／動けません」 would emphasize inability and does not fit the context. Inanimate subjects can occur with potential forms when the meaning warrants it.