Learn Japanese | Minna No Nihongo Lesson 17 Grammar

Summary

In this Japanese lesson, we focus on the knife form of verbs, a key grammatical structure used in informal and negative requests, expressing obligation, and stating things that don't need to be done. The knife form is derived from the masu form, with specific conjugations for different verb groups. Learners will explore how to form sentences like 'please don't do something,' 'must do something,' and 'don't need to do something,' along with how to make the object the topic of a sentence and express deadlines. This lesson provides practical examples and is essential for improving conversational Japanese.

Takeaways

• 😀 **Knife Form of the Verb**: The knife form (verb + ない) expresses the negative form of the verb, meaning 'not to do' or 'do not'. It is used in informal contexts.
• 😀 **Group 1 Verb Conjugation**: For Group 1 verbs, change the final **-masu** form to **-nai** (e.g., **食べます (tabemasu)** → **食べない (tabenai)**).
• 😀 **Group 2 Verb Conjugation**: For Group 2 verbs, simply replace **-masu** with **-nai** (e.g., **見る (miru)** → **見ない (minai)**).
• 😀 **Group 3 Verb Conjugation**: Irregular verbs like **する (suru)** and **来る (kuru)** also follow the same pattern with exceptions (e.g., **する (suru)** → **しない (shinai)**).
• 😀 **Please Don’t Do Something**: Use the knife form + **でください** to make polite requests for someone not to do something (e.g., **チケットをなくさないでください** - Please don't lose your ticket).
• 😀 **Must Do Something**: Express obligation by using the knife form + **なければなりません** (e.g., **本を返さなければなりません** - I must return the book).
• 😀 **Don’t Have to Do Something**: Use the knife form + **もいいです** to express that something is not required or is okay not to do (e.g., **お金を払わなくてもいいです** - You don't have to pay).
• 😀 **Changing the Object to the Topic**: Replace the particle **を** with **は** to make the object the topic of the sentence (e.g., **ケーキを食べないでください** → **ケーキは食べないでください** - As for the cake, please don’t eat it).
• 😀 **Deadline or Time Limit**: Use **までに** to indicate that something must be done by a certain time (e.g., **月曜日までに来てください** - Please come by Monday).
• 😀 **Common Verbs and Usage**: Focus on practicing verbs like **食べる (taberu)** → **食べない (tabenai)**, **行く (iku)** → **行かない (ikanai)**, and **する (suru)** → **しない (shinai)** to master the knife form conjugation.

Q & A

What is the knife form of a verb in Japanese?

The knife form (also called the negative form) of a verb is used to express actions that do not happen. It is derived from the masu-form by modifying the verb ending and adding 'nai'. For example, 'tabemasu' (to eat) becomes 'tabenai' (do not eat).

How do you conjugate verbs in the knife form for Group 1 verbs?

For Group 1 verbs, you change the final 'i' sound (from the 'masu' form) to the 'a' line equivalent, then add 'nai'. For example, 'tabe-masu' becomes 'tabe-nai', and 'kiku-masu' becomes 'kika-nai'.

How do you conjugate Group 2 verbs into the knife form?

For Group 2 verbs, you simply remove the 'masu' ending and add 'nai'. For example, 'tabemasu' becomes 'tabenai', and 'okimasu' becomes 'okinai'.

What is the knife form of Group 3 verbs, and are there exceptions?

Group 3 verbs generally follow the same rule as Group 2, where you drop 'masu' and add 'nai'. However, there are exceptions like 'suru' (to do) which becomes 'shinai', and 'kuru' (to come) which becomes 'konai'.

What is the structure to say 'please don't do [verb]' in Japanese using the knife form?

To say 'please don't do [verb]' in Japanese, use the knife form of the verb followed by 'de kudasai'. For example, 'tabenai de kudasai' (please don't eat), or 'kikanai de kudasai' (please don't listen).

How do you express 'must do' or 'have to do' using the knife form?

To express 'must do' or 'have to do' in Japanese, use the knife form of the verb, followed by 'kariba narimasen'. For example, 'tabenakereba narimasen' (you must eat). This structure indicates that an action is necessary.

What is the difference between 'madeni' and 'made' in terms of deadlines?

'Madeni' refers to a deadline or a specific time by which something must be done. It emphasizes the action being completed by that time. In contrast, 'made' indicates that an action takes place continuously during a time period, not necessarily by the deadline.

How do you say 'you don't have to do [verb]' in Japanese?

To say 'you don't have to do [verb]' in Japanese, use the knife form of the verb followed by 'kuto mo ii desu'. For example, 'tabenakute mo ii desu' (you don't have to eat). This phrase is used to show that the action is not necessary.

What is the usage of 'wa' in the sentence 'as for the cake, please do not eat it'?

'Wa' is used to make the object of a sentence the topic. In the example 'keiki wa tabenai de kudasai' (as for the cake, please don't eat it), 'keiki' (cake) becomes the topic of the sentence, and 'wa' is used instead of 'o' to mark it as such.

Can you provide an example of a question using 'kariba narimasen' for must-do actions?

Yes, an example of a question using 'kariba narimasen' is 'kono hon wa kinyoubi made ni kaeranakereba narimasen ka?' (Do I have to return this book by Friday?). This asks if something must be done by a particular deadline.