Japanese Verbs

Definition: The verb expresses an action, event or state. Verbs in Japanese don't conjugate with the person, number or gender.

Polite Form of Verbs (-masu) ます

People use these verbs for talking to teachers, doctors, older people, or people who don't know well.
Only the verb change when people talk in polite form.
The masu termination can change for conjugate time; see that hereby:

Time of the verb	Termination	Romaji
polite present/future	ます	-masu
polite negative present/future	ません	-masen
polite past	ました	-mashita
polite negative past	ませんでした	-masen deshita

Verbs in Japanese language are divided into two groups or conjugations that have a difference in the formation of their infinitives and stems; but there are only two irregular verbs that have different forms.

Group 1 - consonant, c-stem, u-stem or u-dropping verbs

This group is formed for any verb that doesn't end in -eru or -iru and few verbs that have these terminations. You have the verb stem when you drop the final -u in the verb; you have the infinitive when you add -i at the last of the stem.

English	Dictionary-form	Masu-form
to think	omou	omoimasu
to go	iku	ikimasu
to read	yomu	yomimasu

NOTE: You can consider verbs ending in -au, -iu and -ou as c-stem verbs because these verbs ended respectively in -awa, -iwa and -owa long time ago.

Group 2 - vowel, v-stem or ru-dropping verbs

This group of verbs contains most of the verbs that end in -eru or iru. You can have the stem of these verbs by dropping -ru at the finish; if you want the infinitive, it is the same as the stem.

English	Dictionary-form	Masu-form
to wake up	okiru	okimasu
to eat	taberu	tabemasu
to see, to look at	miru	mimasu

Group 3 - irregular verbs

This group has few verbs that change in other kind of sonjugations. The only way to learn they is by memorizing

English	Dictionary-form	Masu-form
to come/arrive	kuru	kimasu
to study	benkyōsuru	benkyōshimasu
to do/play	suru	shimasu

Plain Form of Verbs

People use these verbs for talking to friends, inmediate family, or associates.
Only the verb change when people need to conjugate in this form of talking.

Plain present/future form

Japanese people use the dictionary form when they need to talk in this form. This form is used to talk in present and furute as well.

Plain negative and past negative form

When we use the plain negative, that used for present and future, words have to end with -nai (ない).
When we use the plain past negative form, words have to end with -nakatta (なかった).
Group 1 - consonant, c-stem, u-stem or u-dropping verbs When people use this form, they have to change the last u-sound to a-sound; after this they add the termination ない or なかった.
The exception for this group is when the verb ends with う (u); if you find this, you have to change the last う to わ (wa) after you add the termination ない or なかった.

English	Dictionary-form	Nai-form	Nakatta-form
to think	omou	omowanai	omowanakatta
to go	iku	ikanai	ikanakatta
to read	yomu	yomanai	yomanakatta

Group 2 - vowel, v-stem or ru-dropping verbs You can have the stem of these verbs by dropping -ru at the finish; you obtain the past form by adding the terminations ない or なかった.

English	Dictionary-form	Nai-form	Nakatta-form
to wake up	okiru	okinai	okinakatta
to eat	taberu	tabenai	tabenakatta
to see, to look at	miru	minai	minakatta
to have/be	iru	inai	inakatta

Group 3 - irregular verbs

This group has few verbs that change in other kind of sonjugations. The only way to learn they is by memorizing

English	Dictionary-form	Negative	Past Negative
to come/arrive	kuru	konai	konakatta
to do/play	suru	shinai	shinakatta
to have/be	aru	nai	nakatta

How express the verb "to be" (iru - aru)

You can express the meaning of to be by the verbs asimasu and imasu, and by the copula desu. You can use desu (です) when one thing is, or is equals to another. You can use arimasu (あります) when you talk about the existence of inanimate objects (here you can include plants, which can't move). You can use imasu (います) when you talk about the existenece of animate objects.
The negative form of desu can be "dewa arimasen" (でわありません), "ja arimasen" (じゃありません), "dewa nai desu" (でわないです) or "ja nai desu" (じゃないです).
Sometimes, you can replace ni arimasu with desu when you describe about the location of something.
Many people translate the verb arimasu with: "have", "there is" or "are".
Some Examples:

This is central park.
これは、中央公園です
Kore wa, chūō kōen desu.

The school is between the hospital and the police station
学校は病院と警察署のあいだにあります
Gakkō wa byōin to keisatsu-sho no aida ni arimasu

Where is Mr. takeshi?
武志さんはどこにありますか
Takeshi-san wa doko ni arimasu ka

Many situations need a high degree of courtesy, like employer talking to its manager, the speaker has to use "gozaimasu" instead arimasu and irasshaimasu instead iru.

Do you have a phone in this hospital? Yes, we do.
この病院に電話を持っていますか？はい、ございます
Kono byōin ni denwa o motte imasu ka? Hai, gozaimasu.

Excuse me, how much is this jeans? It's ¥8,000.
すみません、このジーンズはどのくらいですか？それは 8000 円でございます
Sumimasen, kono jīnzu wa dono kuraidesu ka? Sore wa 8000-en degozaimasu

Uses for the verb "deshô" (でしょう)

This verb comes from desu and has different meaning in different situations for example:

When you use it in questions followed by ka, this verb has the same meaning of "I wonder ...".

I wonder what this is?
これはなんでしょうか
Kore wa nan deshô ka.

When you use it with a rising intonation, it asks for agreement; and it has the same meaning that ne but it's softer and less direct.

This is Mr. Satoshi's book, right?
これは聡さんのほんでしょう
Kore wa Satoshi-san no hon deshô. (rising intonation)

When you use it with a falling intonation, the meaning of the sentence change to probably, must be or almost certainly.
- Hokkaido is probably hot now.
- 福岡は熱いでしょう
- Fukuoka wa atsui deshô. (falling intonation)