Demand, insist 等動詞後接假設語氣子句

• My father demanded that I turn the TV off and go to bed at once. (我父親要求我馬上關掉電視上床睡覺) (正)
• My father demanded that I would turn the TV off and go to bed at once. (誤)
• My father demanded that I turned the TV off and went to bed at once. (誤)

解說：主句的動詞如果是表示建議、要求或命令 (如 demand, insist, order, suggest 等等 )，而且其後的名詞子句含有應該做但還未做的意思，那麼該子句要用假設語氣：主詞 + (should) 原形動詞 + …。