Tai-form ～たい

In Japanese, the "tai-form" happens when you add the -tai ～たい auxiliary adjective to the ren'youkei 連用形 conjugation of a verb, causing it to change to the desiderative mood. In other words, -tai means "want to" in Japanese, and verb-tai means "want to verb."

(beware of homonyms: tai 体, morpheme for "body," and tai 対, "versus." Those are also tai but not what this article is about.)

Manga: Boku no Hero Academia 僕のヒーローアカデミア

Conjugation

-Tee ～てぇ

-Tee ～てー

More Examples

Further Reading

Conjugation

Since -tai is an auxiliary adjective, it's inflected the same way as i-adjectives in Japanese.

katsu 勝つ
To win.
kachi-tai 勝ちたい
Want to win. (base form.)
kachi-takatta 勝ちたかった
Wanted to win. (past form.)

makeru 負ける
To lose.
make-takunai 負けたくない
Not want to lose. (negative form.)
make-takunakatta 負けたくなかった
Not wanted to lose. (past negative form.)

nigeru 逃げる
To run away. To escape.
nige-taku naru 逃げたくなる
To become wanting to escape.
[To start feeling like] wanting to escape.
nige-taku natta 逃げたくなった
Became wanting to escape.
[Felt like] wanting to escape.

nigetakute furueru 逃げたくて震える
To tremble wanting to escape. (te-form.)
Want to escape [so much that you] tremble.
nigetakute kekkon shitai 逃げたくて結婚したい
Want to escape and want marry.
nigetakutemo nigerarenai 逃げたくても逃げられない
Even if [you] want to escape [you] can't escape

Suffixing to Verbs

The -tai auxiliary is added after the ren'youkei 連用形 conjugation of verbs. See:

de aru である
de aritai でありたい
Want to be. (copula.)

donna ningen de aritai? どんな人間でありたい？
What kind of human do [you] want to be?

iru いる
itai いたい
Want to be. (somewhere.)

soba ni itai そばにいたい
Want to be nearby.
[I] want to be [by your side].

suru する
shitai したい
Want to do.

nani ga shitai? なにがしたい？
What do [you] want to do?

kuru 来る
kitai 来たい
Want to come.

asobi ni kitai? 遊びに来たい？
Do [you] want to come play?

au 会う
aitai 会いたい
Want to meet.
kiku 聞く
kikitai 聞きたい
Want to hear.
(often to ask something you want to hear.)
oyogu 泳ぐ
oyogitai 泳ぎたい
Want to swim.
korosu 殺す
koroshitai 殺したい
Want to kill.
yaku ni tatsu 役に立つ
yaku ni tachitai 役に立ちたい
Want to be useful.
shinu 死ぬ
shinitai 死にたい
Want to die.
asobu 遊ぶ
asobitai 遊びたい
Want to play.
nomu 飲む
nomitai 飲みたい
Want to drink.
kiru 切る (godan verb.)
kiritai 切りたい
Want to cut.
kiru 着る (ichidan verb.)
kitai 着たい
Want to wear.

Causative Passive Tai-Form

The -tai auxiliary can also be added to passive and causative conjugations of verbs. For example:

fumu 踏む
To step on.
fumareru 踏まれる
To be stepped on.
(passive conjugation.)
fumaretai 踏まれたい
Want to be stepped on.

yasumaseru 休ませる
To force to rest. (probably not.)
To let rest. (probably yes.)
(causative conjugation.)
yasumasetai 休ませたい
Want to let rest.

mitomeru 認める
To acknowledge.
To admit.
mitomesaseru 認めさせる
To force to admit. (probably yes.)
To let admit. (probably not.)
(causative conjugation.)
mitomesasetai 認めさせたい
Want to force [someone] to admit [something].
Want to make [someone] admit [something].

bikkuri びっくり
Feeling of surprise. (mimetic word.)
bikkuri suru びっくりする
To feel surprised. (suru verb.)
bikkuri saseru びっくりさせる
To make [someone] feel surprised.
(causative conjugation.)
bikkuri saserareru びっくりさせられる
To be made feel surprised.
(causative passive conjugation.)
bikkuri saseraretai びっくりさせられたい
Want to be made feel surprised.
[I] want [you/him/her/someone] to surprise [me].
(causative passive tai-form conjugation.)

Chart

For reference, a tai-form conjugation chart.

-Tee ～てぇ

Sometimes -tai ～たい is pronounced as -tee ～てぇ instead. This is a colloquialism, a contraction in speech, so it's not formal Japanese. Nevertheless, it works the same way as the normal -tai.

geemu yaritai ゲームやりたい
geemu yaritee ゲームやりてぇ
[I] want to play [video-]games.

This -tee ～てぇ is not to be confused with the casual quoting particle tte って.

-Tee ～てー

Sometimes -tee ～てぇ is spelled -tee ～てー instead, with the prolonged sound mark ー. It's the same thing, only spelled differently.

Mista saying イチゴケーキが食いてーんだよっオレはッ！ transcript from JoJo's Bizarre Adventure: Part 5

Manga: Jojo's Bizarre Adventure: Part 5, Jojo no Kimyou na Bouken Ougon no Kaze ジョジョの奇妙な冒険黄金の風

ichigo keeki ga
kuitee-n-da yo'
ore wa'!
イチゴケーキが　食いてーんだよッ　オレはッ！
I want to eat a strawberry cake!

The dots on the furigana are for emphasis.
The small tsu ッ at the end of phrases is for exclamation.

More Examples

やりたいこと

Manga: Aho Girl / Aho Gaaru アホガール

Context: Yoshiko よしこ has been asked what she wants to do.
yaritai koto...
やりたいこと…
A thing [I] want to do...
:thinking:
hito no ue ni tachitai
人の上に立ちたい
[I] want to stand above people.
(as in, looking down upon them, like a king, etc.)
sore wa......それは……
That's......

しにたい

Manga: Demi-chan wa Kataritai 亜人ちゃんは語りたい

Context: Sakie 佐藤早 attempts to look cute.
ja... ja~~~n~
じゃ…じゃ～～んー
Ta... tada!
do... dou desu ka ne~~?
ど…どうですかね～～？
H... how [do I look]?
shinitai しにたい
[I] want to die.
Bonus: manga title

ajin (demi)-chan wa kataritai
亜人（デミ）ちゃんは語りたい
Demi's want to talk.
(*demi is gikun for ajin 亜人, "demi-human.")
kataru 語る
To talk. (about something, in this case, about themselves, probably.)

喜ぶ顔が見たい

Manga: Uchouten Kazoku 有頂天家族

yorokobu kao ga
mitai kara da!
喜ぶ顔が　見たいからだ！
Because want to see rejoicing face. (literally.)
Because [I] want to see [her smiling].

触りたい…モテたい…