かい

Particle (Basic ㊦ 170)

A sentence final particle which marks yes-no questions in informal male speech.

日本語は面白いかい。: Is Japanese interesting?
上野さんはアメリカへ行くのかい。: Is Mr. Ueno going to America?
日本語を勉強するかい。: Will you study Japanese?
このアパートは静かかい。: Is this apartment quiet?
君達は学生かい。: Are you students?
その本は難しいのかい。: Is the book difficult?
あの人は先生なのかい。: Is that person a teacher?

Formation

(i) {V/Adjective い informal}	かい
	{話す /話した} かい	Does (or will)/Did someone talk?
	{高い /高かった} かい	Is/was something expensive?
(ii) {Adjective な stem/ N}	{Ø/だった} かい
	{静か /静かだった} かい	Is/was something quiet?
	{先生 /先生だった} かい	Is/was someone a teacher?
(iii) {V/Adjective い} informal	のかい
	{話す /話した} のかい	Does (or will)/Did someone talk?
	{高い /高かった} のかい	Is/was something expensive?
(iv) {Adjective な stem/ Noun}	{な/だった} のかい
	{静かな/静かだった} のかい	Is/was something quiet?
	{先生な/先生だった} のかい	Is/was someone a teacher?

Notes

1. Since かい is used in informal speech, preceding sentences must be in the informal form. The following sentences are unacceptable.

a. *日本語はおもしろいです(の)かい。
Is Japanese interesting?

b. *上野さんはアメリカへ行きます(の)かい。
Is Mr. Ueno going to America?

2. かい is used only for yes-no questions. Thus, the following sentences are ungrammatical.

a. *どこへ行く(の)かい。
Where are you going?

b. *あの人はだれ(なの)かい。
Who is that person?

In these sentences, だい is used. (⇨ だい)

3. Questions in the Key Sentence (A) pattern and those in the Key Sentence (B) pattern correspond to questions without のです and those with のです in formal speech, respectively.

(⇨ のだ)

4. Questions in female informal speech can be formed by dropping かい in male informal questions and using rising intonation. Examples:

a.日本語はおもしろい(の)？
Is Japanese interesting?

b. 上野さんはアメリカへ行く(の)？
Is Mr. Ueno going to America?

c. あの人は先生(なの)？
Is that person a teacher?