Earlier we learned the explanation mode of speech ～んです (See Lesson 8). The ～んです is the conversational form of more formal のです. Here is a typical situation to use ～んです. Imagine that it's 5:00 p.m. Your coworker just got up from her chair, gathered her belongings, put on a coat, and started towards the door. You can simply ask if she is leaving as in Sentence (1) below without any connection to what just happened. However, Sentence (2) is more natural because you are implying that what just happened explains her action.
(1)
かえりますか。
Are you leaving? (I have no idea. I'm just asking.)
(2)
かえるんですか。
Are you leaving? (Based on what I saw, I'm guessing you are leaving.)
Normally, んです follows the plain forms. With non-past, affirmative nouns and な-adjectives only (e.g., ひまだ and 日曜日だ), だ changes to な before んです.
Non-Past
かえるんです。
It's that (someone) is going home.
かえらないんです。
It's that (someone) is not going home.
たかいんです。
It's that it is expensive.
たかくないんです。
it's that it is not expensive.
ひまなんです。
It's that I'm free.
ひまじゃないんです。
It's that I'm not free.
日曜日なんです。
It's that it's Sunday.
日曜日じゃないんです。
It's that it's not Sunday.
Past
かえったんです。
It's that (someone) went home.
かえらなかったんです。
It's that (someone) did not go home.
たかかったんです。
It's that it was expensive.
たかくなかったんです。
It's that it was not expensive.
ひまだったんです。
It's that I was free.
ひまじゃなかったんです。
It's that I was not free.
日曜日だったんです。
It's that it was Sunday.
日曜日じゃなかったんです。
It's that it was not Sunday.
The plain form of ～んです is ～の (gentle) or ～んだ (blunt), but it does not conjugate to the past tense ～んでした. The question word どうして (Why?) usually requires んです.
The verb すぎる is a る-verb that attaches to other verbs to create a new verb that means to V too much. It attaches to the verb stem (Vます without ます). すぎる can also be attached to adjectives to create a new verb that means to be too (adjective). It attaches to the adjectival stem (the part that does not conjugate) as shown below. すぎる cannot be attached to nouns noted by below.
Stem + すぎる
Examples
のみます ＋すぎる
おさけを飲みすぎました。
I drank too much.
みます ＋すぎる
テレビを見すぎました。
I watched too much TV.
勉強します ＋すぎる
きのう勉強しすぎた。
I studied too much yesterday.
たかい ＋すぎる
あの車は高すぎます。
That car is too expensive.
うるさい ＋すぎる
テレビがうるさすぎます。
The TV is too loud.
むずかしい ＋すぎる
このテストはむずかしすぎた。
This test was too difficult.
やすい ＋すぎる
私のきゅうりょうは安すぎる。
My wage is too cheap.
にぎやか ＋すぎる
ここはにぎやかすぎる。
This place is too lively.
しずか ＋すぎる
そのクラスはしずかすぎる。
The class is too quiet.
げんき ＋すぎる
あの子は元気すぎる。
That child is too energetic.
びょうき ＋すぎる
[Ungrammatical]
Both the verb ～すぎる and the ～たい form can attach to the same verb stem:
およぎすぎる, およぎたい
つくりすぎる, つくりたい
たべすぎる, たべたい
FYI: Some negative forms can be combined with すぎる. To do this, we need to insert an extra sound さ in between as shown below. Caution: Not all negative expressions work in this way.
Stem な + さ + すぎる
Examples
たべない ＋さ＋すぎる
しない ＋さ＋すぎる
ごはんを食べなさすぎる
勉強しなさすぎる
He eats too little.
She studies too little.
おもしろくない ＋さ＋すぎる
この本はおもしろくなさすぎる
This book is too uninteresting.
べんりじゃない ＋さ＋すぎる
べんりじゃなさすぎた
It was too inconvenient.
The V-stem +すぎる pattern is unrelated to the Vて connection we have seen before.
When we are uncertain about certain facts, we use the でしょう ending. でしょう is the tentative form of copula です. The plain form of でしょう is だろう.
あしたは あめです。It will definitely rain tomorrow. あしたは あめでしょう。It will probably rain tomorrow.
Both です and でしょう／だろう sentences are polite sentences. でしょう／だろう expresses speaker's uncertainty and is used in predictions and conjectures (I guess/probably). This pattern can also be used with verbs as in Mr. Tanaka will probably come tomorrow. We call this the Vでしょう pattern. The verb preceding でしょう／だろう is required to be a plain form.
If Ｖでしょう／だろう is turned into a question Vでしょうか, it expresses the notion of ...V, I wonder and can be used to invite comments and opinions from others. In both patterns, the predicate preceding でしょう is normally in the plain form. Note that the overall politeness level of sentences using でしょう is polite despite the fact that a plain form verb is used in the embedded sentences. The phrase たぶん (probably) below is optional.
Q:
田中さんは 来る
でしょうか。
I wonder if Ms. Tanaka is coming.
A:
（たぶん）来ない
でしょう。
She is probably not coming.
Compare this with い-Adj でしょう sentences below.
Q:
あのえいがは おもしろい
でしょうか。
I wonder if that movie is interesting.
A:
（たぶん）おもしろくない
でしょう。
It's probably not interesting.
With な-adjective and noun sentences, the plain copula だ is removed before でしょう.
Q:
田中先生は コーヒーがすき
でしょうか。
I wonder if Prof. Tanaka likes coffee.
A:
（たぶん）すきじゃない
でしょう。
He probably does not like it.
Q:
あれは 田中さんの車
でしょうか。
I wonder if that is Mr. Tanaka's car.
A:
（たぶん）そうじゃない
でしょう。
It's probably not so.
In informal conversation, でしょうか can be でしょう？ or can be shortened to simply でしょ？ as a way of softening the tone of the question.
今、９時でしょ？It's 9 o'clock, right?
The でしょう ending can be in the plain form だろう. A stand-alone statement using だろう is considered very blunt. Beginners of Japanese should avoid だろう as a stand-alone statement. However, the でしょう must be changed to the plain form だろう to be used before と思います (I think probably ... V ...) to express cautiousness of one's guesses and predictions. ～だろうと思います is considered polite.
あしたは雨がふるでしょう。It will probably rain tomorrow. あしたは雨がふるだろうと思います。I think it will probably rain tomorrow.
When you are giving an advice to someone, a comparative sentence
form is used: Doing X is better (than not doing it) or You had better/should V. A plain past verb (Ｖた) is typically used in the affirmative statement.
This pattern contains a modifying clause.
Modifying
Clause
N
Ｖた
ほう
が いい
はやく おきた
ほう
が いいです。
You had better wake up early.
毎日、れんしゅうした
ほう
が いいです。
You had better practice every day.
シャワーを あびた
ほう
が いいですよ。
You had better take a shower.
おふろに はいった
ほう
が いいですよ。
You had better take a bath.
The negative form of Ｖたほうがいい is Vないほうがいい: "Not doing X is better (than doing it)" or "You had better not V/You should not V." Note that plain nonpast negative verb (Ｖない) is used in this structure.
To say that one must do something, we use a Vなくては いけません form or more formal Vなければ なりません. This form has double negative expressions. For example, 行かなくては いけません contains if I do not go(行かなくては), it is not okay (いけません). This gives rise to a strong affirmative meaning: I mustn't not go ⇒ I must go. In casual conversation, ては is contracted to ちゃ and れば is contracted to きゃ.
Plain Neg. V
Vなければ
Vなくては
Negative
食べない
食べなければ
食べなくては
ならない
いけない
(Someone) must eat it.
飲まない
飲まなければ
飲まなくては
ならない
いけない
(Someone) must drink it.
行かない
行かなければ
行かなくては
ならない
いけない
(Someone) must go.
来ない
来なければ
来なくては
ならない
いけない
(Someone) must come.
しない
しなければ
しなくては
ならない
いけない
(Someone) must do it.
With contraction (ければ きゃ／ては ちゃ) in casual conversation
食べない
食べなきゃ
食べなくちゃ
ならない
いけない
(Someone) must eat it.
飲まない
飲まなきゃ
飲まなくちゃ
ならない
いけない
(Someone) must drink it.
行かない
行かなきゃ
行かなくちゃ
ならない
いけない
(Someone) must go.
来ない
来なきゃ
来なくちゃ
ならない
いけない
(Someone) must come.
しない
しなきゃ
しなくちゃ
ならない
いけない
(Someone) must do it.
Examples:
日本語で話さなくてはいけませんでした。
日本語で話さなければなりませんでした。 I had to speak in Japanese.
明日
の朝は７時に起きなくちゃいけない。 明日の朝は７時に起きなきゃいけない。 I have to get up by 7 o'clock tomorrow.
シンデレラは夜の１２時までに家に帰らなくてはいけなかった。 シンデレラは夜の１２時までに家に帰らなくてはならなかった。 Cinderella had to go home by 12 midnight.
The final negative form いけません or なりません can be replaced by semantically negative expressions such as だめ (no good), etc.
この薬
を飲まなくちゃだめよ。You have to take this medicine.
In a casual conversation, obligations/requirements can be softened further by dropping the final negation.
If you replace the first negation of Vなくてはいけない (You must V) with a simple Vて form, you can create a negative expression Vてはいけない (You must not V). This is the prohibition or denial of permission form --- Vてはいけない (Literally, this means it is not okay if you V). This was introduced in relation to the permission form (Vてもいいですか: May I V?) in Lesson 12.
A:
これ、見てもいいですか。 Is it okay even if I see this? [May I see this?]
B:
いいえ、見てはいけません。 No, it's not okay if you see it. or No, you may/must not see it.
In a casual conversation ては can be shortened to ちゃ:
A:
これ、見てもいい？ May I see this?
B:
ううん、見ちゃいけない。 No, you may/must not.
or
A:
これ、食べてもいい？ May I eat this?
B:
あ、食べちゃだめよ！ Oh, you may/must not eat it.
If you use a negative て-form (Vなくて) in the permission form (Is it okay not V?), you can create a permission for NOT doing something:
A:
これ、読まなくてもいいですか。 Is it okay even if I don't read this?
B:
いいえ、読まなくてはいけません。 No, you must read it.
How do you respond negatively to each of the following questions? (Hint: Only the underlined part will change.)
行ってもいいですか。Is it okay even if I leave? / May I leave? いいえ、⇒
The Vないでください form (= negative of Vてください) expresses a request NOT to V. For example, 行かないでください means Please don't go. The kanji for down下 can be used to write ください 下さい.
Plain Vない
で
ください
食べない
で
ください
Please don't eat it.
飲まない
で
ください
Please don't drink it.
しない
で
ください
Please don't do it.
行かない
で
Don't go. [Casual]
Restate the following requests as requests not to V.
The う-verb しる (lit. to get to know) refers to a change of states from not knowing to knowing something. しる is written in kanji as 知る. To describe a current state of someone's knowledge (e.g., I know something), you need to use its resultant state form 知っている.
私はスミスさんを知っています。前に会ったことがありますから。 I know Mr. Smith. I have met him before.
Unlike other resultant state expressions, the negative form of 知っている is exceptional---it is 知りません, not 知っていません.
私はスミスさんを知りません。会ったことがありませんから。 I don't know Mr. Smith. I have never met him.
More examples:
A:
「となりのトトロ」というアニメを知って(い)る？ Do you know an anime called 'Tonari no Totoro'?
B:
うん、知って(い)る。 or ううん、知らない。 Yes, I do. or No, I don't.
The simple past form of 知る verb (知りました, 知った) can be used when you are referring to a past event that led someone to learn about something/someone.
私はアメリカに行った時、スミスさんを知りました。 I came to know (= learned about) Mr. Smith when I went to America.
FYI: スミスさんを知っています and スミスさんを知ります do not mean the same thing. The former means Someone knows Smith while the latter means Someone comes to know Smith. Similarly, スミスさんを知りました means Someone came to know/learned about Smith.
With non-past, affirmative nouns and 
or can be shortened to simply 
