幾時why do幾時why are？

先睇英文問句句式，係動詞先於主詞。有冇question words（who / what / when / where / which / why / how ）都係一樣。

例：
why do you like him?
問o既係 you like him o既原因。 動詞係like，但不能講 「why like you him?」，於是加插個do，變成：
why do you like him，咁萬一要轉tense／第三身單數時，都o係do度轉，不用影響like

why are you here?
要問o既係 you are here o既原因。動詞係are，但 is/am/are/was/were/have/has/had 都可以用作問句開頭（are you happy? is she ok? has he come?），所以就咁搬去主詞前就得。

即係話，如果動詞唔係 is/am/are/was/were/have/has/had ，問句就要用do/does/did