私はその計画に大反対だ。
I am quite opposed to the plan.

反体制派はすべて旧体制のもとで粛清されました。
All political dissidents were purged under the former regime.

例えば、「喜び」の反対語は「悲しみ」です。
For instance, "delight" is the opposite of "sorrow."

彼女は３０分で反対側についた。
She was across in thirty minutes.

反対党議員はその法案に激怒した。
The members of the opposition party were enraged against the bill.