Japanese has copulas which play the most important part in this language as well as most other languages. Japanese copulas provide the similar ideas with the verbs of existence, which are introduced in the previous chapter. The copulas express equality in most cases. Japanese prepares two types of copulas, one is the plain copula, the other is the polite copula. Firstly, this chapter introduces whole the tenses of the polite copula, which provides the unique forms in order to express the affirmative , while it uses "de"(*1), which is the past participle of the copula, followed by the negative of the verbs of existence in order to express the negative .

• (*1) "De" is usually added to "-'wa" or replaced by "ja", which is a contraction of "de-'wa", to express the negative, however, I pick up only "de" here because "de" is gramatically essential and it is easy to explain the relation between existence verbs, the copula, adjectival verbs.

A chart of the tenses of the polite copula [Kana Table]

	tenses	moods		English	Japanese Polite	Ref. Japanese Plain
A F F I R M A T I V E	present	indicative	certain	am/are/is	dèsu	dà
			uncertain	am/are/is probably	deshòu	daròu
		subjunctive		would be
	past	indicative	certain	was/were	dèshita dàtta desu(*1)	dàtta
			uncertain	was/were probably	dàtta deshou	dàtta darou
		subjunctive		would have been
	future	indicative	certain	will be	dèsu	dà
			uncertain	will be probably	deshòu	daròu
N E G A T I V E	present	indicative	certain	am/are/is not	de ari-masèn de nà-i desu(*1)	de nà-i
			uncertain	am/are/is not probably	de nà-i deshou	de nà-i darou
		subjunctive		would not be
	past	indicative	certain	was/were not	de ari-masèn deshita de nà-katta deshou(*1)	de nà-katta
			uncertain	was/were not probably	de nà-katta deshou	de nà-katta darou
		subjunctive		would not have been
	future	indicative	certain	will not be	de ari-masèn de nà-i desu(*1)	de nà-i
			uncertain	will not be probably	de nà-i deshou	de nà-i darou

• (*1) colloquial variants ( not used in formal conversations )

Before introducing sentences which are composited with copulas, this chapter introduce particle "'wa". Particle "'wa" has many features as you read it from many Japanese grammar books. Especially, this particle is famous for the contrary of "ga" and "'wa". In this chapter, I define particle "'wa" as a subject marker to explain sentences easily, although I redefine it in the later chapters. You can use "ga" as well as "'wa", however, particle "'wa" is generally used as a subject marker in sentences with the copulas. Particle "ga" gives a strong nuance to sentences when it is used with the copulas.

How to use the polite present forms

Case 1a

• (K): ウィリアムは ドクターです。
• (J): Whiriamu 'wa dokutah' desu.
• (E): William is a doctor.

Case 1b

• (K): ウィリアムは ドクターで ありません。
• (J): Whiriamu 'wa dokutah' de ari-masen.
• (E): William is not a doctor.

Case 1c (*1)

• (K): ウィリアムは ドクターですか。はい、そうです。いいえ、そうで ありません。
• (J): Whiriamu 'wa dokutah' desu ka? Hai, sou desu. Iie, sou de ari-masen.
• (E): Is William a doctor? Yes, he is. No, he isn't.

Case 1d (*2)

• (K): だれが ドクターですか。ウィリアムが そうです。
• (J): Dare ga dokutah' desu ka? Whiriamu ga sou desu.
• (E): Who is a doctor? William is.

Case 1e (*3)

• (K): これは なにですか。それは ペンです。
• (J): Kore 'wa nani desu ka? Sore 'wa pen desu.
• (E): What is this? It is a pen.

• (*1) "Sou" is a demonstrative noun. In most cases, Japanese can omit a pronoun when it is imaginable in a context. However, a demonstrative noun can not be omitted before the copulas.
• (*2) When the subject of sentences is a interrogative noun, "ga" must be used as a subject marker. because a interrogative noun is always the most important word in sentences. they should be marked strongly.
• (*3) You must not use "(X)Anata 'wa nani desu ka?" in Japanese, as well as "(X)What are you?" in English, because this direct expression to ask human attributes gives the listener a rude nuance. You use other indirect expressions, for example, "Anata 'wa nani wo shite i-masu ka?" in Japanese, as well as "What do you do?" in English.

How to use the polite past forms

Case 1a

• (K): ウィリアムは ドクターでした。
• (J): Whiriamu 'wa dokutah' deshita.
• (E): William was a doctor.

Case 1b

• (K): ウィリアムは ドクターで ありませんでした。
• (J): Whiriamu 'wa dokutah' de ari-masen deshita.
• (E): William was not a doctor.

Case 1c (*1)

• (K): ウィリアムは ドクターでしたか。はい、そうでした。いいえ、そうで ありませんでした。
• (J): Whiriamu 'wa dokutah' deshita ka? Hai, sou deshita. Iie, sou de ari-masen deshita.
• (E): Was William a doctor? Yes, he was. No, he wasn't.

Case 1d (*2)

• (K): だれが ドクターでしたか。ウィリアムが そうでした。
• (J): Dare ga dokutah' deshita ka? Whiriamu ga sou deshita.
• (E): Who was a doctor? William was.

Case 1e (*3)

• (K): これは なにでしたか。それは ペンでした。
• (J): Kore 'wa nani deshita ka? Sore 'wa pen deshita.
• (E): What was this? It was a pen.

• (*1),(*2),(*3) Please refer the above list.

How to use the polite subjective present forms

Case 1a

• (K): ウィリアムは ドクターでしょう。
• (J): Whiriamu 'wa dokutah' deshou.
• (E): William is probably a doctor.

Case 1b

• (K): ウィリアムは ドクターで ないでしょう。
• (J): Whiriamu 'wa dokutah' de na-i deshou.
• (E): William is not probably a doctor.

This list does not introduce the interrogative sentences with the subjunctive forms, because they are not simple correspondence to the indicative sentences. They contain courteous nuance.

How to use the polite subjective past forms

Case 1a

• (K): ウィリアムは ドクターだったでしょう。
• (J): Whiriamu 'wa dokutah' datta deshou.
• (E): William was probably a doctor.

Case 1b

• (K): ウィリアムは ドクターで なかったでしょう。
• (J): Whiriamu 'wa dokutah' de na-katta deshou.
• (E): William was not probably a doctor.

This list does not introduce the interrogative sentences with the subjunctive forms, because they are not simple correspondence to the indicative sentences. They contain courteous nuance.

The copulas do not have these types of inflections, although the subject of a sentence is a motional object which has wills like human beings, animals and so on. When you express these moods, you use ordinary verbs "naru" which means "to become", "suru" which means "to do", and so on.

Adjectival verb is a unique part of speech in Japanese. There is no counterpart in English. Adjectival verb is regarded as "to be" + adjective in English. It has the tense forms in the inflections. Firstly, this chapter introduces whole the tenses of the adjectival verbs which provide the unique forms for the affirmative, while they use "-ku" + the negative of the verbs of existence for the negative. Next, the adjectival verbs provide adjectival usages and adverbial usages with their inflections. However, I skip explanation about them. I will explain them in later chapters.

A chart of the tenses of the adjectival verbs [Kana Table]

	tenses	moods		English	Japanese Polite	Ref. Japanese Plain
A F F I R M A T I V E	present	indicative	certain	am/are/is bright	ákarù-i desu	ákarù-i
			uncertain	am/are/is bright probably	ákarù-i deshou	ákarù-i darou
		subjunctive		would be bright
	past	indicative	certain	was/were bright	ákarù-katta desu	ákarù-katta
			uncertain	was/were bright probably	ákarù-katta deshou	ákarù-katta darou
		subjunctive		would have been bright
	future	indicative	certain	will be bright	ákarù-i desu	ákarù-i
			uncertain	will be bright probably	ákarù-i deshou	ákarù-i darou
N E G A T I V E	present	indicative	certain	am/are/is not bright	ákaru-ku ari-masèn ákaru-ku nà-i desu(*1)	ákaru-ku nà-i
			uncertain	am/are/is not bright probably	ákaru-ku nà-i deshou	ákaru-ku nà-i darou
		subjunctive		would not be bright
	past	indicative	certain	was/were not bright	ákaru-ku ari-masèn deshita ákaru-ku nà-katta desu(*1)	ákaru-ku nà-katta
			uncertain	was/were not bright probably	ákaru-ku nà-katta deshou	ákaru-ku nà-katta darou
		subjunctive		would not have been bright
	future	indicative	certain	will not be bright	ákaru-ku ari-masèn ákaru-ku nà-i desu(*1)	ákaru-ku nà-i
			uncertain	will not be bright probably	ákaru-ku nà-i deshou	ákaru-ku nà-i darou

• (*1) colloquial variants ( not used in formal conversations )

How to use the polite present forms

Case 1a

• (K): ランプが あかるいです。
• (J): Ranpu ga akaru-i desu.
• (E): The lamp is bright.

Case 1b

• (K): ランプが あかるく ありません。
• (J): Ranpu ga akaru-ku arimasen.
• (E): The lamp is not bright.

Case 1c

• (K): ランプが あかるいですか。はい、あかるいです。いいえ、あかるく ありません。
• (J): Ranpu ga akaru-i desu ka? Hai, akaru-i desu. Iie, akaru-ku arimasen.
• (E): Is the lamp bright? Yes, it is. No, it isn't.

Case 1d

• (K): なにが あかるいですか。ランプが あかるいです。
• (J): Nani ga akaru-i desu ka? Ranpu ga akaru-i desu.
• (E): What is bright? The lamp is.

Case 1e

• (K): ランプは どうですか。あかるいです。
• (J): Ranpu 'wa dou desu ka? Akaru-i desu.
• (E): How is the lump. It is bright.

How to use the polite past forms

Case 1a

• (K): ランプが あかるかったです。
• (J): Ranpu ga akaru-katta desu.
• (E): The lamp was bright.

Case 1b

• (K): ランプが あかるく ありません でした。
• (J): Ranpu ga akaru-ku arimasen deshita.
• (E): The lamp was not bright.

Case 1c

• (K): ランプが あかるかったですか。はい、あかるかったです。いいえ、あかるく ありません でした。
• (J): Ranpu ga akaru-katta desu ka? Hai, akaru-katta desu. Iie, akaru-ku arimasen deshita.
• (E): Was the lamp bright? Yes, it was. No, it wasn't.

Case 1d

• (K): なにが あかるかったですか。ランプが あかるかったです。
• (J): Nani ga akaru-kata desu ka? Ranpu ga akaru-katta desu.
• (E): What was bright? The lamp was.

Case 1e

• (K): ランプは どうでしたか。あかるかったです。
• (J): Ranpu 'wa dou deshita ka? Akaru-katta desu.
• (E): How was the lump. It was bright.

How to use the polite subjective present forms

Case 1a

• (K): ランプが あかるいでしょう。
• (J): Ranpu ga akaru-i deshou.
• (E): The lamp is probably bright.

Case 1b

• (K): ランプが あかるく ないでしょう。
• (J): Ranpu ga akaru-ku na-i deshou.
• (E): The lamp is not probably bright.

This list does not introduce the interrogative sentences with the subjunctive forms, because they are not simple correspondence to the indicative sentences. They contain courteous nuance.

How to use the polite subjective past forms

Case 1a

• (K): ランプが あかるかったでしょう。
• (J): Ranpu ga akaru-katta deshou.
• (E): The lamp was probably bright.

Case 1b

• (K): ランプが あかるく なかったでしょう。
• (J): Ranpu ga akaru-ku na-katta deshou.
• (E): The lamp was not probably bright.

This list does not introduce the interrogative sentences with the subjunctive forms, because they are not simple correspondence to the indicative sentences. They contain courteous nuance.

The adjectival verbs do not have these types of inflections, although the subject of a sentence is a motional object which has wills like human beings, animals and so on. When you express these moods, you use ordinary verbs "naru" which means "to become", "suru" which means "to do", and so on.

A relation between existence verbs, the copula and adjectival verbs [Kana Table]

				English	the existence	the copula	adjectival verbs
polite	affirmative	past	certain	was/were	ari-mashita	deshita	-katta desu
			uncertain	was/were probably	atta deshou	datta deshou	-katta deshou
		present	certain	am/are/is	ari-masu	desu	-i desu
			uncertain	am/are/is probably	aru deshou	deshou	-i deshou
	negative	past	certain	was/were not	ari-masen deshita	de ari-masen deshita	-ku ari-masen deshita
			uncertain	was/were not probably	na-katta deshou	de na-katta deshou	-ku na-katta deshou
		present	certain	am/are/is not	ari-masen	de ari-masen	-ku ari-masen
			uncertain	am/are/is not probably	na-i deshou	de na-i deshou	-ku na-i deshou
plain	affirmative	past	certain	was/were	atta	datta	-katta
			uncertain	was/were probably	atta darou	datta darou	-katta darou
		present	certain	am/are/is	aru	da	-i
			uncertain	am/are/is probably	aru darou	darou	-i darou
	negative	past	certain	was/were not	na-katta	de na-katta	-ku na-katta
			uncertain	was/were not probably	na-katta darou	de na-katta darou	-ku na-katta darou
		present	certain	am/are/is not	na-i	de na-i	-ku na-i
			uncertain	am/are/is not probably	na-i darou	de na-i darou	-ku na-i darou