I'm certain that you were brainwashed at that time.
Without a doubt, you were brainwashed at that time.
例文一:
You were definitely brainwashed at that time. Don't beat up on yourself.
間違いなく君はその時、洗脳されていたと思う。自分を責めないでね。
例文二:
I'm certain that you were brainwashed at that time. Don't blame yourself.
間違いなく君はその時、洗脳されていたと思う。自分を責めないでね。
例文三:
There is no doubt that you were brainwashed at that time. You gotta forgive yourself.
間違いなく君はその時、洗脳されていたと思う。自分を責めないでね。
・"at that time"の代わりに"at the time"も言えます。"that"を使ったら特定の時期を指摘します。
・"you were brainwashed"の代わりに"you had been brainwashed"も言えます。
・私が追加した「自分を責めないでね」は"don't blame yourself"・"don't beat up on yourself"・"you gotta forgive yourself"にしました。"don't blame yourself"は普通の言い方で、"don't beat up on yourself"はカジュアルです。"you gotta forgive yourself"は意訳です。