Grammar JLPT Level N5 - Lesson 15

たい is an auxiliary verb that is used to express things that you would like to do (want). To use たい, it needs to be added to the same conjugation base form of a verb that ます would be attached to.

• 今夜(こんや)はピザが食(た)べたい。
  Tonight, I want to eat pizza.
• プロの歌手(かしゅ)と歌(うた)いたい。
  I want to sing with a professional singer.

When using たい, the thing that is 'wanted' can either be marked with を, or が. The difference in nuance is that something marked with が is considered to be wanted more. たい is conjugated in the same way as い-Adjectives, meaning that the negative, past, or past-negative forms may also be used.

• 虫(むし)は食(た)べたくない。
  I don't want to eat insects.
• 警察官(けいさつかん)になりたかった。
  I wanted to become a police officer.
• 昔(むかし)は先生(せんせい)になりたくなかった。
  In the past, I did not want to become a teacher.

たい is only used for expressing things that 'you' want, or repeating information/asking questions about what other people want. It may not be used to make guesses about what other people 'may' want, unless asking them directly.

• 何(なに)が食(た)べたい?
  What do you want to eat?
• オレンジジュースを飲(の)みたかったの？
  Did you want to drink orange juice?