Masu Form vs Dictionary Form: Polite-to-Plain Verb Practice

Change the verb form without changing the action. Distinguish a dictionary form from a plain past or negative form, which are also plain but are not dictionary forms.

Reverse the conjugation through the verb group

For 一段 verbs such as 食べる, the polite form removes る and adds ます: 食べます. 五段 verbs use the appropriate i-row sound before ます: 書く becomes 書きます and 読む becomes 読みます. Work backwards through that pattern when you see a polite form.

Do not simply replace ます with る in every verb. 読みる is not the dictionary form of 読みます. The irregular verbs する and 来る give します and 来ます. Some verbs ending in る, such as 帰る, are 五段 verbs, so their class must be learned.

Plain is a wider category

読まない and 読んだ are plain forms, but neither is the dictionary form 読む. These questions ask for the non-past affirmative form unless another target is explicitly named.

Examples to read before you practise

Try six questions

Try these self-check questions from memory, then compare your answers with the explanations. For automatic checking and saved progress, open the related practice after this article.

1. 食べます → dictionary form

2. 読みます → dictionary form

3. 書く → polite non-past affirmative

4. 帰る → polite non-past affirmative

5. します → dictionary form

6. 来ます → dictionary form; kana accepted

Answer key and explanations

1. 食べる / たべる — 食べる is an 一段 verb.

2. 読む / よむ — Undo the 五段 i-row stem.

3. 書きます / かきます — く becomes き before ます.

4. 帰ります / かえります — 帰る is a 五段 verb.

5. する — する is irregular.

6. 来る / くる — The dictionary form is 来る, read くる.

Keep learning

• Study verb groups.

• Study masu form.

• Study plain polite.

• Open the related three-step lesson.

• See your daily study and review schedule.

Related lessons

• Japanese Te Form Input Drill: Six Conjugations You Need to Recall

• Ta Form vs Te Form: Change the Ending Without Losing the Sound Pattern

• Toki vs Mae Ni Practice: When Something Happens and Before It Happens