Do you recall his name? 你还记得他的名字吗?
Does that look familiar? 这个看起来眼熟吗? Does that sound familiar? 我说的你听起来熟悉吗? Does that ring a bell? 我所说的,使你想起什么来了吗? I don't recall that offhand. 那个我一时记不起来.
I'm blanking out. 我完全忘的一干二净。 I forgot which is which. 我忘了哪个是哪个。
I always confuse the two. 这两个我常混淆不清。 I have a poor memory. 我的记性差。