I've forgotten what the firm he works for is called.
我已經忘記他所在公司的名稱。
Have you forgotten about that money I lent you last week?
你忘記上星期我借給你的那筆錢了吧？
I'd forgotten the keys, which didn't help matters.
我忘記帶鑰匙了，這讓情況更糟。
Are you sure you locked the gate? You could easily have forgotten.
你肯定鎖上大門了嗎？你很可能是忘了。
Oh sugar! I've forgotten my book!
哎呀！我忘帶書了！