how to say: I don't remember in mandarin?
Hi,
Sorry for my pinyin being without tones, I hope you can answer me anyway

I would say "I don't remember": wo bu jide
Is that a common way to say this?
I saw in an article that it can be said this way: wo xiang bu qilai le
is it correct? which of those would be more common to hear? is there a better way to say?

Thanks!!

Question

how to say: I don't remember in mandarin?
Hi, 
Sorry for my pinyin being without tones, I hope you can answer me anyway

I would say "I don't remember": wo bu jide
Is that a common way to say this? 
I saw in an article that it can be said this way: wo xiang bu qilai le
is it correct? which of those would be more common to hear? is there a better way to say?

Thanks!!

Answer

1) I think "to remember" is a bit different to "to recall", then: “记”=remember, "想起来"=recall.  So, "想不起来" could happen at a sudden occasion, and "想起来" later，while "不记得" almost means the memory is lost.
2)“不记得”is a bit more formal“想不起来”, only a little bit. It's very possible ppl don't differ them in normal talks.
3)better way to say?  我想不起什么更好的说法来了。

Answer

You can also say 我忘了(wo3 wang4 le), which means I forgot.

Answer

不好意思， 我忘记了。

Bu hao yi si， wo wang ji le.

Answer

“我不记得”（wo bu jide） is more fml. than “我想不起来了”（wo xiang bu qilai le）. Both are widely used in writing and verbal.