Subject + 忘记 + Object / Clause
The verb 忘记 (wàngjì) means "to forget" and is used when someone fails to remember something. It can take a noun or a clause as its object. For example, 忘记那个晚上发生的事 means "forget what happened that night."
我差点忘记今天是你的生日了!
Wǒ chàdiǎn wàngjì jīntiān shì nǐ de shēngrì le!
I almost forgot that today is your birthday!
别忘记带钥匙,上次你就忘了。
Bié wàngjì dài yàoshi, shàng cì nǐ jiù wàng le.
Don't forget to bring your keys; you forgot last time.
她始终无法忘记那段美好的时光。
Tā shǐzhōng wúfǎ wàngjì nà duàn měihǎo de shíguāng.
She has never been able to forget that wonderful time.