Japanese linguistically distinguishes events in which someone acts on things (e.g., Someone opens the door) from events in which something just happens (e.g., The door opens [by itself]). Transitive verbs are used for the former, and intransitive verbs are used for the latter. In English, this distinction is often blurred because the same verbs can be used to refer to these phenomena. Not all Japanese verbs come in transitive-intransitive pairs, but the following are some common ones. Note that the direct object of a transitive verb is marked by を while no direct objects are used for intransitive verbs.

	Transitive Verbs (Someone acts upon something)		Intransitive Verbs (Something happens by itself)
●	ドアを あける。(る-V) Someone opens the door.		ドアが あく。(う-V) The door opens (by itself).
●	ドアを しめる。(る-V) Someone closes the door.		ドアが しまる。(う-V) The door closes (by itself).
●	電気を つける。(る-V) Someone turns on the light.		電気が つく。(う-V) The light comes on.
●	電気を けす。(う-V) Someone turns off the light.		電気が きえる。(る-V) The light goes off.
●	コンピュータを こわす。(う-V) Someone breaks the computer.		コンピュータが こわれる。(る-V) The computer breaks/goes out of order.
●	子どもを おこす。(う-V) Someone wakes up children.		子どもが おきる。(る-V) Children wake up.
●	おゆを わかす。(う-V) Someone boils water.		おゆが わく。(う-V) Water boils.
●	コップを おとす。(う-V) Someone drops a glass.		コップが おちる。(る-V) A glass drops.
●	Xに 水を いれる。(る-V) Someone puts water into X. Xに 本を いれる。 Someone puts a book into X.		Xに 水が はいる。(う-V) Water is put into X. Xに 本が はいる。 A book is put into X.
●	水を だす。(う-V) Someone turns on water. りょうりを だす。 Someone serves/brings out a meal.		水が でる。(る-V) Water comes out. りょうりが でる。 A meal is served/brought out.
●	へやを よごす。(う-V) Someone makes the room dirty.		へやが よごれる。(る-V) The room becomes dirty.
●	ちゅうもんを きめる。(る-V) Someone decides on the order.		ちゅうもんが きまる。(う-V) The order is decided on.
●	かぎを かける。(る-V) Someone locks (something). 時間を かける。 Someone takes time. お金を かける。 Someone spends money. 電話を かける。 Someone makes a phone call.		かぎが かかる。(う-V) (Something) becomes locked. 時間が かかる。 (Something) takes time. お金が かかる。 (Something) costs money. 電話が かかる。 Phone rings.
●	車を とめる。(る-V) Someone stops the car. 水をとめる。(う-V) Someone stops water.		車が とまる。(う-V) The car stops. 水が とまる。(る-V) Water stops (coming out).
●	びょうきを なおす。(う-V) Someone cures an illness. テレビを なおす。(う-V) Someone repairs the TV.		びょうきが なおる。(う-V) The illness is cured. テレビが なおる。(う-V) The TV is repaired.
●	ごはんを のこす。(う-V) Someone leaves/retains some food.		ごはんが のこる。(う-V) Some food remains.
●	ごみを かたづける。(る-V) Someone puts away trash.		ごみが かたづく。(う-V) Trash is put away.
●	おきゃくを のせる。(る-V) Someone loads passengers.		おきゃくが のる。(う-V) Passengers get on.
●	おきゃくを おろす。(う-V) Someone drops off passengers.		おきゃくが おりる。(る-V) Passengers get off (the train, etc.).
●	メッセージを まわす。(う-V) Someone sends the message around.		メッセージが まわる。(う-V) The message goes around.
●	れんしゅうを つづける。(る-V) Someone continues the practice.		れんしゅうが つづく。(う-V) The practice continues.

If verbs come in a pair of transitive and intransitive verbs, here are "rules of thumb" to distinguish them based on the verb forms. Note that the following rules may sometimes make wrong predictions.

• If one of the pair of verbs ends with ～す (e.g., わかす, おこす, なおす, だす, etc.), that verb is likely to be a transitive verb that inflects like a う-verb.
  Or
• Transitive verbs tend to end with /-eru/ and inflect like a る-verb (e.g., あける, しめる, つける, きめる, etc.) except those that end with れる /-reru/ (e.g., きれる: be cut, とれる: come off).
  

When these verbs are used in the ～ている construction, transitive verbs describe on-going (or repeated) actions and intransitive verbs describe resultant states. In an informal conversation, the い sound in ～ている/～ていない can be dropped: ～てる/～てない.

	Transitive Verbs (On-going actions)		Intransitive Verbs (Resultant states)
●	ドアを あけています。 Someone is opening the door.		ドアが あいています。 The door is open (as a result).
●	ドアを しめています。 Someone is closing the door.		ドアが しまっています。 The door is closed (as a result).
●	おゆを わかしています。 Someone is boiling water.		おゆが わいています。 Water is boiling-hot (as a result).
●	いぬを いれています。 Someone is letting the dog in.		いぬが はいっています。 The dog is inside (as a result).
●	ごみを おとしています。 Someone is dropping trash.		ごみが おちています。 Trash is on the floor (as a result).
●	でんきを けしています。 Someone is turning off lights.		でんきが きえています。 The lights are out (as a result).

1.	A:	テレビがついていますか。		A:	Is TV on?
	B:	いいえ、ついていません。つけましょうか。		B:	No, it's not on. Shall I turn it on?
	A:	ええ、つけてください。		A:	Yes, please turn it on.
	B:	(Bはテレビのボタンをおしました。)		B:	(B pused the TV button.)
		つきませんね。こわれたみたいです。			It won't come on. It seems broken.

2.	A:	おさらは かたづいている？		A:	Are the plates put away?
	B:	かたづいてないよ。		B:	No, they are not.
	A:	じゃ、かたづけて。		A:	Please put them away.
	B:	はい。(Bはおさらを一まいおとしました。)		B:	Okay. (B dropped a plate.)
		カーペットをよごしてごめんなさい。			Sorry for soiling the carpet.
	A:	ふくもよごれちゃったね。		A:	Your clothes are dirty, too.

B's apology sounds sincere because she uses a transitive verb ("I soiled it") even if she did not mean to do so.

3.	A:	このピザ食べてもいい？		A:	May I eat this pizza?
	B:	いいけど、私もあとで食べるから、 少しのこしといて。		B:	Yea, but I'll eat some later, too, so leave some.
		(later) ピザがのこってない！			(later) Pizza is all gone!
	A:	あれ？　テーブルにおいといたよ。 いぬが食べちゃったのかな？		A:	What? I put it on the table. Our dog ate it all, I wonder.

B's surprise is expressed by an intransitive verb ("What happened?").

To check the state of something, you can use this open-ended question: Xは どうなっていますか.

4.	A:	ガスレンジは どうなっていますか。		A:	What has become of/happened to the gas range?
	B:	ガスレンジは ついています。		B:	The gas range is on.

The combination of two verbs, Vて+しまう has two meanings --- (1) Someone does something completely (similar to saying "up" as in "I used up my energy"), or (2) Something happens unintentionally. The first implies that someone has control over his/her actions like deliberately carrying out a plan. In contrast, the second implies a lack of self-control---someone does not have any control over the action/event, and the latter is often accompanied by a sense of regret. Which is implied depends on speaker's assumption whether or not he/she has self-control over the action/event.

• そのケーキを食べてしまいました。
  I ate the cake completely (as I planned). OR
  I ate the cake completely (I couldn't help it---the cake looked too tempting to resist).
  
  
• きょうは日本語のクラスがあったけど、休んでしまいました。
  I had a Japanese class today, but I took a day off (deliberately). OR
  I had a Japanese class today, but I took a day off (and I couldn't help it).
  
  
• 友だちからかりたコンピュータをこわしてしまいました。
  I broke the computer I borrowed from my friend (deliberately). OR
  I broke the computer I borrowed from my friend (and I couldn't help it).

If the events are natural events or described by intransitive verbs, only the second interpretation (a lack of self-control) is possible.

• きょうはピクニックに行くつもりだったけど、雨がふってしまいました。
  I intended to go on a picnic today, but it rained (and it's so unfortunate).
  
  
• 勉強していたら、電気がきえてしまいました。
  When I was studying, the light went off!
  
  
• 友だちからかりたコンピュータがこわれてしまいました。
  The computer I borrowed from my friend broke completely (and there was nothing I could do).

The Vてしまう can be contracted to Vちゃう in a casual conversation.

• テレビを見てしまう。　⇒　テレビを見ちゃう。
• コーラを飲んでしまった。　⇒　コーラを飲んじゃった。
• その本を読んでしまいます。⇒　その本を読んじゃいます。
• さとうをつかってしまいました。　⇒　さとうをつかっちゃいました。

Earlier we learned S1と、いいです pattern (I hope S1). This earlier pattern is based on the more general S1と、S2 pattern. This pattern refers to a relationship between two facts: what inevitably happens (S2) when the condition in S1 is met (If/When S1 happens, S2 inevitably happens). S1と、S2 can also refer to a habitual sequence of events (Whenever S1 happens, S2 happens).

	S1と、 (Condition)	S2 (Result)
●	このボタンをおすと、	電気がつきます。	If you push this button, the light will come on.
●	べんきょうしないと、	せいせきがわるくなる。	If you don't study, your grade will worsen.
●	家に帰ると、	てがみが来ていました。	When I arrived home, there was a letter. [= was there to be found after I arrived]

The following grammatical constraints apply to S1と、S2:

1. S1 must be the non-past (usually, plain) form regardless of whether the events happen in the past, present or future.
2. S1 always has to happen before S2 happens (the same requirement as in Vたら).
3. Since both S1 and S2 refer to facts, S2 cannot be an expression of request or command (Vて下さい), intention (Vつもりです), desire (Vたい), volition (Vましょう), suggestion or advice (Vたほうがいい), or other willingness to do something. If you want to express these, use the Vたら form: メロンがあったら、買ってきて下さい.
4. If S1と、S2 refers to a one-time, past sequence of events, S2 cannot refer to actions with self-determination by the same person. In other words, S2 must be a natural consequence of S1---a surprise event that the subject of S1 has no control over. (The same constraint applies to Vたら.) This constraint does not apply to a habitual or repeated past sequence of events.

• 春になると、あたたかくなります。(habitual events)
  Whenever spring arrives, it becomes warm.
  
  
• ねないと、病気になりますよ。(habitual events)
  If you don't sleep, you will be sick.
  
  
• 子どものとき、公園に行くと、よくいぬとあそびました。(habitual past events)
  During my childhood, when I went to the park, I often played with the dog.
  
  
• まどをあけたと、部屋(へや)が寒くなりました。
  When I opened the window, the room became cold.
  [Ungrammatical (violation of Constraint 1): S1 must use a non-past form (even for a past event).]
  
  
• あした学校に行くと、バスで行きます。
  [Ungrammatical (violation of Constraint 2): S1 does not happen before S2. S1 and S2 happen at the same time. To correct this, use 時: あした学校に行く時、バスで行きます.]
  
  
• そつぎょうすると、日本ではたらきたいです。
  [Ungrammatical (violation of Constraint 3): S2 expresses desires or volitions. To correct this, use たら: そつぎょうしたら、日本ではたらきたいです.]
  
  
• （私は）家に帰ると、母に電話しました。
  [Ungrammatical (violation of Constraint 4): S2 expresses self-determination by the same person. To correct this, use 時: （私は）家に帰った時、母に電話しました.]

In formal writing, the S1と、S2 pattern is used more commonly than the S1たら、S2 pattern.

The V1+ながら、V2 expresses parallel actions that happen simultaneously by the same person. In the V1ながら、V2 construction, V2 is the main action performed by the subject of the sentence, and V1 is the subordinate action.

	Subordinate Action	Main Action
	V1+ながら	V2
●	音楽を聞きながら	べんきょうする。		I listen to music while I study.
●	けいたいで話しながら	うんてんしたら	あぶない。	It's dangerous if you talk on the cell phone while you are driving.
●	新聞を読みながら	食べては	いけない。	You must not read a newspaper while eating.

The corresponding English construction is V1 While V2-ing, and the main action is often expressed by V2 (Don't talk on the cell phone (V1 = subordinate action) while driving (V2 = main action).). However, the main action in English can also be expressed by V1 depending on the context (e.g., Let's watch football (V1) while drinking beer (V2)).

If the subjects of two actions are different, ながら cannot be used. This restriction does not apply in English.

• 兄がテレビを見ながら、私がラジオを聞いた。 [Ungrammatical in Japanese]
  While my brother watched TV, I listened to the radio. [OK in English]

We have seen two conditional forms in Lesson 19--- S1たら、S2 and S1と、S2. The ～ば、よかった form is another conditional form that states If X had happened, it would have been better. This form implies a counterfactual situation (= the event that did not happen) that you regret and it is often translated as I wish X.

	S1 ば、 (Condition)	S2 (Result)
●	もっとべんきょうすれば	よかったです。	I wish I had studied more. [= If I had studied more, it would have been better.]
●	はやく家に帰れば	よかったです。	I wish I had gone home earlier. [= If I had gone home earlier, it would have been better.]
●	雨がふらなければ	よかったです。	I wish it hadn't rained. [= If it had not rained, it would have been better.]

The ば-conditional forms are obtained as follows. Note that ば after なら is often dropped. That is, what we learned as なら conditional form earlier is actually the short form of ならば. Contraction of ～ければ is ～きゃ.

	Plain form	Rules	ば-form
●	おもしろい ない	Change い to ければ.	おもしろければ なければ	if it is interesting if there is nothing
●	べんりだ 雨だ	Change だ to なら(ば).	べんりなら(ば) 雨なら(ば)	if it is convenient if it rains
●	みる おきる	For る-verbs, change る to れば.	みれば おきれば	if (someone) sees it if (someone) wakes up
●	つかう あく はなす まつ よむ かえる	For う-verbs, change /-u/ to /-eba/ (/aku/ ⇒ /akeba/)	つかえば あけば はなせば まてば よめば かえれば	if (someone) uses it if (something) opens if (someone) speaks if (someone) waits if (someone) reads if (someone) returns
●	する くる		すれば くれば	if (someone) does it if (someone) comes

FYI: If いいです is used instead of よかったです, the ～ば、いいです pattern can express a desirable but unlikely future event: あした、雨がふらなければ、いいです (I hope it won't rain tomorrow). This can also be said using the S1と、S2 pattern (e.g., 雨がふらないといいです) or the S1たら、S2 pattern (e.g., 雨がふらなかったらいいです).