Potential Form vs Koto Ga Dekiru: Express Ability with Two Patterns

Compare 読めます with 読むことができます. Both can express ability, but they require different verb forms before their endings.

Build one pattern at a time

For a 五段 verb, the potential form moves to the e-row and adds る: 読む becomes 読める and 書く becomes 書ける. For an 一段 verb, the standard potential form adds られる after removing る: 食べられる. する becomes できる.

The longer construction uses dictionary form plus ことができる: 読むことができます. Do not put the polite form 読みます directly before こと, and do not add a second ability ending by writing 読めることができます for this simple task.

Keep the claim specific

日本語が読めます states reading ability, not every aspect of knowing Japanese. Also, standard potential 食べられる and colloquial 食べれる occur in different registers. The exercise explicitly asks for the standard form so that the scoring target is clear.

Examples to read before you practise

Try six questions

Use the interactive practice below. Type only the requested expression. Kanji and kana alternatives are accepted where listed in the answer key. Completing a question records a result; opening the answer key does not.

1. 読む → polite potential

2. 書く → dictionary potential

3. 食べる → standard dictionary potential

4. する → dictionary potential

5. 泳ぎます → form before ことができます

6. 読むことが（　）。 Complete the polite ability expression.

Answer key and explanations

1. 読めます / よめます — む becomes め before the potential ending.

2. 書ける / かける — く becomes け plus る.

3. 食べられる / たべられる — Use the standard 一段 ending られる.

4. できる — する has potential できる.

5. 泳ぐ / およぐ — Use dictionary form before こと.

6. できます — できます completes the construction.

Keep learning

• Study potential form.

• Study koto ga dekiru.

• Open this six-question practice set.

• See your daily study and review schedule.

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